In The Blood

Make of yourself an honest man, and there will be one less rascal in the world.

Thomas Carlyle 1803 – 1855

It behooves a man to know human nature in general and his own nature in particular, at least in your humble servant’s opinion, which, along with $1.25, will buy you a soft drink in a can.

Has Gentle Reader ever wondered why people do some of the things they do? While it makes perfect sense to work diligently for the necessities of life such as food, clothing, and housing, we do many unnecessary things that yield no apparent profit, for example gardening, despite fruits, vegetables and even flowers being easier and cheaper to purchase in a grocery store. And how about the large, lush green lawns and ornamental plants and trees we install around around our homes and maintain at great effort and expense, plants that serve no practical purpose but cost us time and money and other resources?

What whips drives us to these excesses?

I daresay this isn’t just a guy thing, either. Many ladies insist on weaving, knitting, and sewing clothing and home furnishings by hand even when mass-produced, inexpensive products of similar quality and utility can be readily purchased from stores anywhere. It just doesn’t make sense, and I say that as a husband that, at the behest of She Who Must be Obeyed, has spent thousands of dollars on CNC sewing machines with unobtanium armatures and smoothie attachments all to make quilts that never spend a second on a bed and seldom even see the light of day.

What is this madness that has her gripped in its talons?

But I fear the madness runs deeper still, for many males of the species spend inordinate amounts of time and money buying trucks, ATVs, clothing that makes them look like trees, camping gear and weapons of death and destruction (aka WODADs) in preparation for hunting season, a time when otherwise sane people don orange costumes and chase Bambi around the mountains and forests just to obtain the most expensive meat to be found anywhere in the world. It’s just nuts.

And don’t even get me started about fishing. A good time was had by all during these hunting and fishing expeditions, but the benefits are impossible to calculate. It just isn’t logical…

Woodworking is useful for making housing and furniture and many of the tools essential to civilization, but what about woodworking as a hobby? Isn’t it quicker, easier, less expensive and more sliver-free to buy pre-fabricated houses assembled on-site with bolts and furniture made of MDF, plastic and steel excreted by Chinese factories? Of course it is, so what is this friking parasite madly manipulating levers in our brains compelling us to make these things with our own hands instead?!

I don’t know why we do these things, I only know we want to do them and that doing them gives us satisfaction. But I do have a humble theory I will present for Gentle Reader’s consideration, just for giggles.

I believe that the habits and actions that successfully preserved our ancestors long enough for them to produce and raise each generation of humans became imprinted in each subsequent generation’s DNA.

Successful farmers survived since ancient times leaving descendants with their genes. I suspect it is the farmer gene that compels so many of us to grow fruits and vegetable and surround our homes and cities with lawns and plants, a form of agriculture similar to that which kept our ancestors from starvation. It’s the only possible explanation for the universal compulsion to plant stuff.

The children of women who spun, wove, knitted and sewed clothing and bedding survived cold winters inheriting the sewing gene. I’m not sure where smoothie attachments fit into the equation, but sewing machines are clearly part of the compulsion.

The children of successful hunters and fishermen survived too. The compulsion to perform these activities is still strong in many, your humble servant included. I’m sure you’ll agree that the ritual of talking around the evening camp fire about the big one that got away while saber tooth tigers and cave bears prowled in the shadows beyond the fire is much much older than recorded history.

Somewhere not far out on a limb of Gentle Reader’s family tree are hundreds, perhaps thousands of ancestors that shaped lumber to make houses to protect and keep their families warm, and beds, tables, benches and chests to make life cleaner and more pleasant. This is a healthy and noble urge, one that, like farming, sewing, hunting and fishing has been useful in keeping body and soul in intimate contact for many thousands of generations in humanity’s past.

My father inherited the woodworking gene from a carpenter ancestor, one of two brothers that left England in the 1600’s to travel to South Carolina by leaky boat. It appears I in turn have passed it down to my sons and grandsons. I am glad of this for mayhap I hear the toenails of wolves clicking on stones in the dark shadows just outside the firelight just now, so a solid door of thick hewn oak with a sturdy cross-bar may come in handy before the morning.

But for now, please ignore the snuffling and scratching noises at the door, pull up a chair by the fire and let’s get started on that chess game, shall we?

YMHOS

Waiting for dark, and dinner

If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

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Salt, Rice, Sake and a Prayer

Mother troll introducing her two handsome, well-dressed sons as suitors to a fairy princess. A difficult choice!

But when the fairy sang the whole world listened to him. Stephen felt clouds pause in their passing; he felt sleeping hills shift and murmur; he felt cold mists dance. He understood for the first time that the world is not dumb at all, but merely waiting for someone to speak to it in a language it understands. In the fairy’s song the earth recognized the names by which it called itself.

Susanna Clarke, Jonathan Strange & Mr Norrell

Most of the posts to the C&S Tools blog are focused on how to select, maintain and use woodworking handtools. But in this article your humble servant would like to examine the relationship between supernatural influences and construction jobsite safety from a Japanese perspective.

We will also briefly examine a traditional way to deal with supernatural beings in order to increase both safety during construction and the welfare of those who will occupy the completed structure.

Gentle Readers involved in construction, either as customer or worker, may find this article informative and maybe even helpful.

Supernatural Beings

Your humble servant has often sensed unexplainable presences when alone in deep forests, high mountains, dark caves, and open deserts where human influence is absent. These irrational feelings may spring from an overactive imagination, or perhaps the gentle ministrations of a butter-fingered baby-sitter when I was small, but I’m not alone in my perceptions because humans in all parts of the world have felt similarly about certain places on the earth such as hills, groves, and caves since before recorded history. What about you?

The peoples occupying the heavily-forested islands of Japan have, since ancient times, believed that spirits reside in trees, hills, rocks, rivers and of course the ground. Indeed, Japan’s indigenous religion, called Shinto, which can be translated as “The Path of the Gods,” is a vague belief system based almost entirely on this amorphous perception. It is no coincidence that Shinto has heavily influenced Japanese architecture and carpentry traditions.

If one believes that supernatural beings reside in trees, groves, mountains, water and even rocks, it’s not a stretch to believe that some of those beings, or spirits, are naughty and some are nice. Besides, the bad things that happen to us can’t all be blamed on Fortuna, right?

Since most people can neither see nor readily converse with these beings or spirits, and they don’t give a rodent’s ruddy fundament about what judges and lawyers do and say, how can we protect ourselves from their naughty tendencies, especially when human activities evoke their ire?

Indeed, what human activities piss-off vengeful supernatural beings in nature? Loud music? Social injustice? Wearing socks with sandals? Nah, none of those. In the case of Japan it has been traditionally held that clearing and grubbing trees and vegetation and excavating soil for construction projects is asking for trouble from the supernatural beings that call such places home. Accidents, injuries and even deaths during construction work are believed to be a direct result of such activities, and the malevolent effects of PO’d spirits can make entire buildings dangerous, unhealthy and unlucky places.

So how does one keep potentially dangerous spirits happy? A traditional approach is a ceremony called the Jichinsai.

Jichinsai Ceremony

The name of this common ceremony is pronounced jee/cheen/sah/ee, and is written 地鎮祭 in Chinese characters as used in Japan.

The first character 地, pronounced “Ji” or “Chi,” means ground or earth. The second character means “weight” as in “paper weight,” but it also means to “suppress” or “calm.” The last character is pronounced “sai” and can also be read “matsuri,” meaning ceremony or festival.

There are records of Jichinsai being performed in Japan as early as AD 690. The background of the ceremony is the belief indigenous to Japan, and found in many other locations around the world since ancient times, that spirits reside in places and even plants.

I think I participated in my first Jichinsai in Japan in 1987. I have since attended many in Japan and even a couple in the United States.

I like to think of the Jinchinsai as a ceremony to keep mischievous pixies sleepy and to hide the building and workers from Murphy’s attentions.

The Jichinsai ceremony is typically performed prior to the beginning of a construction project. Its goal is to show respect to and appease the local spirits, and thereby forestall them from seeking revenge for the contractor’s rude disruption of their happy homes.

The ceremony accomplishes these goals by providing offerings of food and booze and greeting to the spirits, showing proper respect, a bit of entertainment, and saying prayers informing them of the construction plans and asking for their protection. Basically, salt, munchies, wine and flattery followed by a polite, well-phrased request, just like a good pickup line. (ツ)

Nowadays, this ceremony has been appropriated by Shinto priests hired to conduct the ceremony, but it is neither Buddhist nor even Shinto in origin, having roots older than formal religion.

Indeed, while priests saying theatrical prayers and dressed in silk brocade robes and oh so goofy hats add to the pageantry, and they insist the efficacy, of the ceremony, in your humble servant’s opinion they add little but cost because, at its heart, the only true participants in the ceremony are the workmen who will perform the construction work, those who will live in or use the completed building, and the spirits that reside in the vegetation and ground to be disturbed. But it is human nature to enjoy and even find meaning in pageantry. If not, the Academy Awards program would have been canceled years ago for being such a boring, preachy stinker. And besides, priests need work too. 

Indeed, if only the builder conducts and attends the ceremony, that is sufficient for purposes of promoting safety for himself and his workers during the construction work, although the Owner, if he doesn’t participate, could arguably miss out on some of the blessings possibly provided by the ceremony such as his safety and prosperity in using the land and building.

A Shinto priest dressed in silk robes, wooden shoes and lacquered hat conducting a Jichinsai ceremony for a corporate construction project. A specialist subcontractor has erected the tent and provided seating and props. Notice the wooden stand with offerings of salt, foods and wine, standing bamboo at the four corners, and Cleyera Japonica cuttings below and behind. At this point in the ceremony, the Priest has sung several prayers and scattered bits of paper around. The pile of sand in the foreground is still undisturbed, but towards the end of the ceremony the Client’s representatives will poke it with a wooden hoe to let the spirits know dirt work will start soon. The step-by-step program for the ceremony is listed on the board to the right. Participants in the ceremony are required to stand, clap hands, bow, drink a drop of demon rum and make plant offerings several times. It is an extremely solemn business.

Groundbreaking ceremonies have been around for a long time in other nations too. Nowadays in the West, they have degraded to a photo opportunity for publicity hounds like politicians and business owners, but the tradition of dedicating, blessing and/or sanctifying the ground upon which a building will stand has ancient roots in Christian and Pagan traditions too. 

Nowadays most versions of the ceremony are centralized on a wooden table set up on the site where the building will be constructed surrounded by green bamboo cuttings stuck into the ground forming a square. A rope is strung around these poles and pieces of paper cut into a special pattern particular to Shinto ceremonies are hung from these ropes. 

Various offerings are placed on the table, always including at least rice, salt and sake. Some additional offerings might include products from the sea, such as fish, and products from the mountains, such as the various herbs and vegetables that supernatural beings like to munch on. Fruits are often included as well. Other than fish, meat is not included.

The general contractor usually hosts the ceremony, sets the stage, makes other arrangements and pays the costs. Of course priests don’t work for free so the cost of the ceremony is included in the contractor’s construction contract amount, although it is seldom shown as a line item. Often, however, the GC will inquire before bidding if the Owner desires a Jinchinsai to ascertain if the cost should be included or not. 

I won’t go into all the details of what goes into a Jinchinsai because it would take months of research and a book I do not have the time to write.

The following links are to YouTube videos of an actual Jichinsai with all the trimmings. Video 1 Video 2

Why Perform a Jichinsai Ceremony?

I mentioned above that I do a lot of work for international corporate Clients. Indeed, Gentle Reader no doubt uses their products daily. These are corporations that are decidedly non-religious and are careful to avoid allowing religious influence to become apparent in their business dealings. So how do they justify spending money and time on a ceremony intended to deal with metaphysical influences? The reasons, as I understand them, are twofold: (1) Peace of mind; and (2) Avoidance of blame. 

Let’s examine reason number 1 first.

After many millennia of belief, the local employees of even large international corporations have a fear of malevolent supernatural influences embedded in their DNA, so to actively reject a harmless, basically non-religious, non-controversial tradition intended to protect them may cause undue stress in some individuals.

You don’t believe me? Here’s a true story.

A Ghost Story

Some years ago my team and I were managing a two-phase construction project for a very wealthy and well-known international consumer electronics company.

Phase One included office fitout work and cleanroom construction (tenant improvements) in a leased space in a brand spankin new building located in Yokohama. Although the grade of the completed project was exceptionally high, it was just a temporary facility.

Phase Two, however, was the construction of a large, elegant, high-tech, structurally-advanced building intended for long-term operations. When completed it was without doubt the most beautiful and both technologically and environmentally advanced building in Japan, if I do say so myself.

The Client anticipated hiring hundreds of new engineers to work in both the Phase One and Phase Two spaces, but sadly hiring lagged far behind plan, so even though we had completed the construction work of the Phase One office spaces on-time and installed some nice office furniture too, it was mostly empty.

For many months after most of Phase One was complete, my team and I used the otherwise unoccupied, high-ceiling leased space as our workplace for the planning and design of Phase Two. It was a large, lonely space.

This intense project involved working late into the evening far too often. An exceptionally diligent lady on my team I will call Naoko worked many evenings alone in these empty spaces. After a few months Naoko became seriously stressed and complained about hearing strange noises and feeling like she was being watched by unkind eyes. Even I thought the place felt creepy. Soon the entire team was feeling weird and stressed.

I took Naoko’s complaints seriously because, when it comes to workplace stress, perception is absolutely reality. And so I shifted our base of operations to a less-comfortable pre-fab jobsite office sooner than originally planned to get the team out of that creepy place. Problem solved.

Indeed, there may have been something unlucky about the leased building because, besides the hiring SNAFU, the Client’s operations in the building accomplished much less than planned. Indeed, serious and very unpleasant acrimony developed among the Client’s employees that occupied it. When the new building was completed, they too moved out of the leased space as soon as humanly possible.

We later learned from the general contractor that developed, constructed and owned the office building that it stood smack dab on an old graveyard. Hmmmm.

Did I mention that the Client decided to not perform a Jinchinsai prior to construction of the leased space?

A Good Beginning

For the new building, however, the Client wisely decided they wanted to avoid the risk of not doing a Jichinsai, a decision that was welcomed by the general contractor and the thousands of workmen that were involved in its construction.

Despite having 14 large crawler cranes lifting heavy stuff and drilling deep piles, and 600+ heavy trucks carrying soil out of and concrete and materials into the extremely tight and dangerous site daily, and over 10,000 workmen on-site for months on end, we only experienced one injury when a sheet-metal worker cut his hand on some sharp metal scrap, and one accident when a careless iron-worker managed to start a small localized fire in some urethane concrete blankets with a cutting torch.

Another worker with a well-documented history of a bad ticker had a fatal heart attack on the way home one day, but that incident was ultimately deemed unrelated to the construction work.

This safety record was a miracle in my book. Was it a direct result of the Jichinsai? Who can say. I only know that if we hadn’t done the ceremony, and a serious accident or death had occurred on the job site, the Client would have been blamed for carelessly not performing the ceremony and the work would probably have suffered as a consequence.

And this illustrates the ultimate reason for conducting a Jichinsai ceremony: Better to be safe than sore. 

The Simplified Jichinsai

There are various approaches to pacifying possibly malevolent spirits. One is the full-blown Jichinsai ceremony, of course. Another is a simpler, humbler, and less-expensive way, because, after all, what the ceremony boils down to is a sincere offering of salt, rice and sake and a silent request to the resident spirits for forbearance.

One such simplified example is quietly and routinely performed by either the general contractor or his steel erection subcontractor. They simply place a small mound of salt, another of uncooked rice, and a small cup of sake wine at the base of the first column erected, then the employees of the GC and/or the erection team offer a silent prayer. No muss, no fuss, no silly hats, but it’s still taken very seriously by the workers.

When I was a self-employed contractor, I would do something similar. Before beginning any excavation, I would politely place a small mound of salt, another of rice, and a small cup of local wine on the ground at what would later become the center of the completed building or renovation and leave it overnight. I would also lay a branch of the local vegetation, be it tree or bush, beside the offerings. Before leaving at the end of the day, I would offer a silent prayer to heaven, and whoever else might bother to listen, that the job would proceed without accident or injury to any workmen involved, and that it would remain on-schedule and under-budget.

Did it work? I don’t know, but the only serious jobsite injuries and deaths I have experienced over the years have been where a Jichinsai of some sort was not performed. Cheaper insurance you will never find.

One Beloved Customer located in the Pacific Northwest of the United States Coast recently began construction on a small but elegant outbuilding using beautiful Port Orford Cedar wood with traditional and extremely intricate interlocking Japanese handcut joints and hand-plane-finished, and natural stone foundations with fitted posts.

The photos below are of his simple Jichinsai. No accidents or injuries so far!

YMHOS

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may tree spirits drop limbs on me from a great height.

Tenant Improvement Work in Japan – Part 1: A Work, B Work, C Work

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Toranomon Hills Business Tower (left foreground, under construction), and Toranomon Hills Mori Tower (right background), two Class 1 office buildings in Tokyo, Japan in which my firm is currently managing construction work.

“Any fool can write a book and most of them are doing it; but it takes brains to build a house.” 

Charles Fletcher Lummis

This article is not focused directly on woodworking or woodworking tools per se, but rather on how to go about leasing space in Japan, and contracting for construction in that space. The wood and tools come afterwards.

I have never seen the subject of Tenant Improvements (or Tenant Fit-out, as it is called in some countries) addressed in writing outside of real estate dealings and construction projects in Japan, and never on the internet. It will no doubt sound like gibberish to many, but those involved in the real estate or commercial construction industries may find it interesting and maybe even profitable.

You should find it especially interesting if you anticipate leasing space in a building in Japan, or doing construction work in a leased space here. This little bit of basic insider knowledge could make you look like a genius.

You Don’t Know What You Don’t Know

Too often I have worked with people and companies, who shall remain nameless, that made planning decisions without the insight described below. The results were sometimes painful.

The most jarring incidents I have seen occurred with people and companies accustomed to real estate leasing and construction projects in their own countries, but who are willfully ignorant of how things are done here in Japan, and insist that the knowledge and experience they possess is applicable without significant adaptation. In response to corporate pressure, and based on a poor understanding of local realities, these lost souls plan the process to fit their abilities confident they will be able to manipulate the Landlord and contractors through a combination of their devastating charm, superhuman negotiation skills, and the leverage afforded by their company’s wealth and fame. In a leasing market of 96% occupancy, such people frequently wake up to find reality kneeling on their neck while carving tasteless limericks into their forehead.

The most pitiful prospective tenants I have seen came to Tokyo from Hong Kong and Singapore. They sent younger employees to handle the leasing, always with good English-language abilities, but no experience outside their own country or mainland China, where they had only dealt with unsophisticated and hungry brokers, consultants, and contractors to whom they could dictate terms and conditions. Absolutely convinced the Hong Kong or Singapore way of doing things is the only way, they waste time, money and goodwill banging their heads against a stone wall never realizing that Japan has an advanced real estate and construction industry with many companies hundreds of years old and possessing technical capabilities few, if any, American or European companies can even think to match.

Delays, budget overruns, embarrassment, pattern baldness, and sudden employment changes ensue.

I prefer to avoid all that drama. How about you?

The Tokyo Office Leasing Market

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A commercial office building under construction. The completed building is of exceptionally high quality.

High unit lease rates and the tricks of the trade described below have made owning and leasing out office/retail space in a Class 1 office building in Tokyo one of the world’s most profitable, risk-free, and steady investments.

You won’t see this fact written about in financial publications, however, because it’s small club that’s difficult to join and with few opportunities for foreign financial consultants to make a profit in the fly’s lifespan time-window they allow for investments to bear fruit. But there are a few savvy real estate investors outside of Japan who know the value of owning the right building in the right place in a Japanese metropolitan area and wish they could get a piece of it.

A handful of foreign companies and investors have succeeded here, especially in the hospitality industry, but it is a long row that few non-Japanese companies have the patience or connections to successfully hoe.

All of the terms mentioned in this post are related to a tenant space (usually office or retail) leased in buildings in one of Japan’s major cities, and constructing the improvements (aka “tenant improvements,” “TI’s,” or “tenant fit-out”) needed to make the space usable.

So let’s dive in and paddle like a duck in an alligator farm.

A Work

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A jobsite in Tokyo with extensive drilled-piling work underway. 12 cranes and 6 drill rigs are working concurrently. 600 trucks entered and left the jobsite daily during this foundation work.

“A Work” (short for “Category A Work”) is a contractual term in Japan which refers to construction work performed directly on the “Base Building” on behalf of a Tenant in the building. This type of construction work does not, however, come into play until the building’s construction is complete and the terms of a tenant lease agreement are being negotiated.

“A Work” typically includes any modifications to the base building’s structure, core & shell, mechanical, electrical and plumbing systems, elevators, common areas, etc. If you need to cut holes in the floor slabs for stairs between multiple floors you will lease, or need to add duct space or pipe shafts for your rooftop equipment for instance, it will be A Work.

Owners of high-quality buildings in metropolitan areas are understandably keen to preserve their investment and the income it produces and so will always have their designated contractor perform A Work at their direction but at the Tenant’s expense. This is an important point to keep in mind.

You will have no opportunity to competitively bid A Work, so save yourself the embarrassment of insisting, being rebuffed, and having to explain a strategic error to your board of directors.

Be aware that if you intend to propose to the building Owner or Landlord that the modifications you require will improve or upgrade the base building, and therefore the cost should either be borne or supplemented by them, you will need to conclude those negotiations before you sign the lease, while you have leverage, or the entire cost will be your responsibility.

Please note that it will be your contractual obligation to pay for restoring the building to its original condition, whether the Owner/Landlord actually does it or not, and even if that means downgrading the building. The cost, for instance, of removing/restoring a stairway between floors frequently costs more than the original construction itself. Ouch is right.

We will discuss “Restoration” in a future post in this series.

B Work

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Electrical work underway.

“B Work” is another contractual term you will need to understand. It refers to tenant improvements (aka “tenant fit-out”) “connected” to the base building.

B Work typically includes all mechanical, electrical, lighting, plumbing, HVAC, ductwork, fire life-safety work (fire sprinklers, gas fire suppression systems, fire alarms and emergency lighting, etc), partitions, ceilings, OA floors (raised floors) wall finishes, most floor finishes, blinds and PA systems to be constructed or installed inside the lease space, as well as Tenant-requested BMS systems, emergency generators, chillers and heat exchangers required to service the tenant’s equipment.

Often millwork (cabinets), kitchen, pantries, and sometimes even system furniture to be located within the tenant’s leased space are included in B Work too. The old, bitter joke is that if you turn the building upside down and shake it, everything that doesn’t fall off is either A or B Work. Not a lot left.

B Work too is almost always performed by the Owner/Landlord’s designated contractor(s), often the same ones that constructed the building originally, at highly inflated prices. You won’t see it as line item in the B Work contractor’s cost estimate, but the Owner’s and management company’s hefty cuts are included.

Here is a critical point to grasp: Competitive bidding is not an option for B Work. Your company’s strict procurement rules will therefore be irrelevant, so best to get your procurement department on-board early. But don’t worry, this isn’t the only standard “carved-in-stone” rule your company will need to adapt.

The Tenant normally signs a construction contract directly with the designated B Work contractor(s) but has very little leverage to control construction costs. The Owner/Landlord has no motivation to see these construction costs reduced, you see, and so will not aid you in reducing them. Do you see where this is going?

C Work

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The third type of Work we will discuss in this article is called “C Work.” It includes everything the Tenant wants constructed besides A Work and B Work, including carpet tiles, Audio-visual equipment, IT cabling and servers, Telecom, UPS, security systems (card readers, security sensors and cameras inside tenant spaces) millwork (sometimes), specialty lighting and sound systems, AV systems, and loose furniture. Usually system furniture too, but not always.

Sometimes C Work includes interior partitions, such as glass or metal partitions, that are installed between the OA floor and the ceiling and do not connect directly with the floor slab or overhead structure. This item is often a good opportunity to save costs and is worth negotiating thoroughly before signing any lease. More on this in the “Demarcation Table” section below.

Unlike A and B Work, a Tenant can directly perform C Work using qualified licensed contractors they select. Bidding is entirely possible and construction costs are typically at market prices much less than A Work and B Work, so compared to A Work and B Work, cost savings can be realized.

On the other hand, if you are in a dreadful hurry and/or can’t be bothered to deal with producing drawings and hiring contractors, then asking the B Work contractor to execute your C Work design/build is an excellent, but expensive way to simplify and expedite the process.

You will want to prepare well and plan your lease negotiation schedule to take advantage of the local knowledge your PM team possesses to move as much of A Work and B Work into the C Work column of the Demarcation Table as possible.

The Demarcation Table

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As you probably deduced from my vague definitions of A, B and C Work above, the limits of each type of construction work vary from city to city, landlord to landlord, and from building to building. Sometimes they are negotiable, sometimes not.

The “Demarcation Table,” or more correctly “Construction Work Demarcation Table” 工事区分表 is a document that becomes part of the lease agreement and lists the items of construction work included in A, B, and C Work. As the Tenant, you or your agent must negotiate this document along with the lease.

Careless people sometimes leave this discussion for after the lease agreement, but a wise Tenant will know before beginning negotiations what construction work they will need, what concessions they want, and the likely unit prices they will be charged for construction so that negotiations will go smoothly, the best deal can be obtained, and buyer’s remorse can be avoided.

Having a knowledgeable leasing agent and Project Management team on your side during this critical process will make the process quicker and the results more economical.

Allow me to share a few examples of how to handle the Demarcation Table to your benefit during Lease Agreement negotiations.

For instance, the Landlord may not be willing to discount your lease as much as you like, but if you are prepared in-advance, you may be able to convince him to tweak the demarcation table so some expensive construction items, and/or items you want your contractor to perform, are shifted from B Work to C Work allowing you more control at less cost.

Or perhaps you need to install a backup generator to service your IT system. You will need space to install it, and provisions for a fuel tank, fuel lines, and exhaust and cable shafts/ducts. If you negotiate carefully and early, you may be able to get the space for free, or at a discount. After the lease is signed, however, fat chance.

After they perform their electrical load calculations, some tenants are surprised to learn that, while the building overall has adequate power for their needs as confirmed during due diligence, they will need to install a transformer or three to step the power up or down or change the phasing to meet their power requirements. Labs, cleanrooms, kitchens, and video studios, for example, use a lot of juice.

Transformers often must be mounted outside, perhaps on a balcony or more likely on the building’s roof. Transformers, switchgear and electrical panels are definitely “long-lead items” that take months to fabricate/procure, as are the steel electrical cabinets to house them. If you know you will need this equipment you can adjust your schedule and budget early, and negotiate concessions from the landlord for space, and access. But if you wait until the lease is already signed, your leverage will be gone, baby, gone.

Why does all this matter, you ask? It matters because once you sign the lease, you are committed and have no choice but to pay whatever price the Landlord and his contractor want to charge you for A Work and B Work, and comply with their schedule. There are ways to minimize the pain, but on your own you won’t have the relationships, the data, the local experience, or the language skills to make meaningful headway. Conversely, you most definitely will have the ability to increase the costs of A Work and B Work by creating hard feelings with the Landlord through confrontational Trumpian-style negotiation techniques.

Don’t push or allow your real estate leasing representative to negotiate your lease in a rude, condescending, or pushy manner because, if he does, the Landlord will make you pay for it ten times over later in cashy money.

There are many other details related to A work, B Work and C Work you need to identify through due diligence, engineering consultation, cost estimating, scheduling and negotiations. Experience in the locale and possessing good relations with the Landlord, contractors and consultants are critical. You will need a good Project Manager with local experience to ensure this work gets done quickly and completely, unless, that is, you enjoy explaining budget overruns, schedule delays, and inadequate facilities to your boss or board of directors.

Building Permits

In many countries, the process of obtaining building permits/approvals is a huge uncertainty, and sometimes a crap-shoot that delays schedules and wastes huge amounts of time and money. In Japan’s metropolitan areas, however, building permits are typically not required for tenant inprovements. There typically aren’t even any inspections by the building department.

The one sure exception to this general rule is the Fire Department, who will need to review the fire sprinkler and other fire/life-safety drawings the B Work contractor will prepare and submit to the Fire Department. The Fire Department will also insist on inspecting the building at the completion of construction, but before occupation. This is a “hard stop” to construction that cannot be avoided, and sometimes consumes a week or more. Careful preparation by a respected B Work contractor can accelerate this process.

As the Tenant, you have no role in this process other than to stay out of the way.

If your legal beagles get their panties in a knot out of concern about potential non-compliance of the Work with local codes and regulations, tell them to take a handful of Xanax with a cold brew and just chill because the general contractor has full legal responsibility for defective and/or non-compliant work. I have never seen permits or approvals become a problem.

You would be wise, however, to have your Project Management team in Japan perform regular inspections and report to you until the construction is complete and the project receives occupancy permission from the Fire Department.

In the next post in this series we will examine the design process for a tenant fit-out project in Japan.

YMHOS

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If you have questions or would like to learn more about our tools, please use the form located immediately below titled “Contact Us.” Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, incompetent facebook, thuggish Twitter, or a driver for a US Congressman and so won’t sell, share, or profitably “misplace” your information.

The Carpenter and the Angel

For a change of pace, I would like to share this charming folktale from Kagoshima Prefecture, Japan, of a sort traditionally told to small children.

We originally posted this little story about a year ago, but since those pesky pixies seem to have pulled it down, we are re-publishing it today for Japan’s Labor Thanksgiving Day holiday and because Tengo was such a great workman (or at least labor producer).

I have included photo extracts from the Kasuga Gongen Genki E (春日権現験記絵) scrolls painted in 1309 on silk using silver and gold paints, showing carpenters working on the Kasuga Temple jobsite.

My children and I enjoyed this story. Perhaps you and yours will too.

The Tale of Tengo and Tenjin

Once upon a time there was a very good carpenter. But he was sad because he lived alone, so he asked the prettiest girl in the village to be his bride.

She did not want to marry, but to put him off without hurting his feelings, she decided to charge him with an impossible task. 

“If you will build me a big house with 60 tatami mats in a single day, then I will marry you.” (60 tatami mats = approx 99 square meters = 1065 sqft based on the standard modern tatami mat) 

The carpenter was shocked by this demand, but because he wanted her for his bride, he boldly accepted the challenge saying: “I will build you this house in one day.” 

His voice rang with confidence as he said this, but he despaired in his heart knowing he could not build such a large and beautiful house in one day. He thought to himself  “ What shall I do, what shall I do?”

But never fear, because as you have probably guessed, our carpenter was no ordinary fellow to give up easily. Before long he came up with a plan.

He made 2,000 dolls out of straw and breathed on each while casting a magical spell transforming them all into human carpenters. 

The carpenter and his 2,000 man crew then went to work.

A cross-section of the Carpenter’s plan (dimensions are in Sun (pronounced soon) and meters). Notice the coved & coffered ceiling in the family room on the right.
Images from the “Kasuga Gongen Genki E,” completed in 1309
The Master Carpenter and his helper use a water trough as a water level for layout. He uses a vertical string of a fixed length with a plumb bob attached to check the high stringline’s height above the water’s surface to adjust the line to be approximately level.
A crew of 3 workmen excavate a hole and compact the soil at the intersection of two low stringlines installed by the Master Carpenter in preparation for placing a natural foundation stone, probably intended to support a main post. Notice the shovel: a one-piece wooden body with a joined “T” handle with a steel or iron cutting edge affixed. Bleeding-edge technology at the time.
The carpenter and his young helper in the drawing’s upper half use a sumitsubo (inkpot) to snap a straight line on a timber in preparation for splitting it into boards. At the lower right, the master carpenter uses his sumitsubo inkline as a plumbline to orient his steel square to vertical against the log’s end. At the same time, he directs his mellow-looking partner at the opposite end to make a matching vertical line using a steel square with a bamboo pen wet with ink from the reservoir of his classic split-tail sumitsubo. Notice how he has used an adze to keep the log from rolling away.
The carpenters in the upper right use chisels to split timbers, while the other workers use adzes to dimension and clean split boards. One appears to be of African persuasion. Notice the classic carpenter’s toolbox at the far right with a leaf-blade saw secured to the lid and a wooden mallet laying next to it on the ground
At the top of this image you can see two carpenters, one shaping the end of a round column and another sawing what appears to be a kumimono bracket with a leaf-shaped saw as he jabbers at his buddy a hundred miles an hour. In the center, more carpenters use spear planes to flatten and smooth boards and a round column after they were adzed. Notice the wood shavings curling from the curved blades, some being pushed and others pulled. Spear planes were used in Japan long before blade-in-block planes became common. The guy working on the board’s right hand end appears to have his thumb stuck in his eye. I hate it when that happens!
Carpenters erecting the building’s structure. No ginpoles, shoes, or tie-offs are in sight. Probably no hardhats either. And the scaffolding is a death trap! Tisk, tisk! What would OSHA say? The planks resting on the scaffold in this image (also visible in the first image and the image directly above) have two square holes cut in each end, perhaps for tying them down to the scaffold. On the other hand, a carpenter in the upper left-hand corner is using his leaf-shaped saw to cut one of these boards, so maybe they are construction lumber and the holes make it easier to hoist the boards by hand to higher elevations. The carpenter at the far right wearing blue and climbing a ladder has an adze at his waist, but I can’t figure out what tool he has in his right hand.
A diagonal view of the coved & coffered ceiling at the family room.
A corner view of the family room coved & coffered ceiling. Notice the coped joints. This work is typically performed by joiners, not carpenters.
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The living room has an even more elegant coved & coffered ceiling with “kumimono” brackets.
The living room’s coved & coffered ceiling in hinoki wood with a carved “rainbow beam” in the foreground. Nice work!

With the assistance of his 2,000 helpers, the carpenter completed building his bride-to-be’s house before the sun went down that day,

Overjoyed, the carpenter flew to the pretty girl’s house to tell her of his success. “I have finished the house you asked for. Please marry me now!”

“Truly?” she asked. Upon inspecting the work she found a big, beautiful house with 60 tatami mats, just as she had asked. “I will marry you.” she said.

And thus the prettiest girl in the village became the carpenter’s bride.

The carpenter and his bride then moved into their happy new home.

Afterwards, the 2,000 carpenters scattered throughout Japan to build houses, temples and bridges and teach many other carpenters how to build beautiful things for many years.

After several happy years had passed, the bride said to her husband “I have been silent up to now, but the time has come to tell you the whole truth. I am not really a human being, but an angel named Tenjin. I came down to earth from the kingdom of heaven. But the time has now come for me to return to heaven.”

The carpenter replied: “Ah, well, now that you mention it, I’m not a human being either, but a carpenter god named Tengo. Let’s both return to heaven together.”

So Tengo and Tenjin rose high into heaven where they still live happily ever after.

The End

YMHOS

If you have questions or would like to learn more about our tools, please use the “Contact Us” form located immediately below. Please share your insights and comments with all Gentle Readers by using the form located further below labeled “Leave a Reply.” We aren’t evil Google, incompetent facebook, or twitchy Twitter and so won’t sell, share, or profitably “misplace” your information.

Timber Frame Water Mill Reconstruction Project, UK Part 1

Written by Guest Author, Gavin Sollars, Timber Frame Carpenter, UK

The village is the token and pride of England; there are usually found in it vestiges of earlier life – cottages, manor-houses, farm-houses, with buildings of more or less historic interest; and who should understand them, their origin, their peculiarity of structure, better than the local carpenter?

Walter Rose, The Village Carpenter 
The reconstruction job site as seen from across the River Test. Notice the green netting installed to prevent things from falling into the environmentally-sensitive river.

Introduction 

I became acquainted with Stan early in 2019 when I decided to look at buying an Ootsuki Nomi. During my search I became skeptical of many of the Japanese tools that are widely available to the European market and, after a lot of research, I came across Stan’s contact details and sent him an email. Stan took a great deal of time to discuss with me what really motivated my purchase, the kinds of things I should take into consideration when looking at Japanese tools and went into detail about the intricacies of Japanese craftsmanship. The information he freely provided was invaluable, and with his help I feel I made a very good choice, and now have a tool that will serve me for my entire career.

I recently updated Stan with some pictures of buildings I had worked on and he asked if I would be willing to share them with the readers of his blog. The overall aim of these ramblings is to describe to you (who Stan calls his “Gentle Readers”) the general outlines of the reconstruction of an 18th century traditionally-jointed timber frame structure in a beautiful area of the English countryside in the summer of 2019. I hope that this article will give you an understanding of the work that was undertaken and also the enthusiasm I have for this archaic variety of building craft and carpentry as a whole. 

Project Background

Timber framing in the UK has enjoyed a resurgence in popularity over the last 30 or so years, with quite a number of small to medium sized specialists in the craft building new ‘post and beam’ style buildings that emulate the traditional frames of the past. These companies are mixing time-honoured design details and timber framing techniques with more modern methods of production: chiefly circular saws and portable chain mortisers to rough out the work. This deep understanding and appreciation of historic building vernacular made my employer (The Green Oak Carpentry Co.) well placed to undertake the reconstruction of this Project.

The Mill prior to 2018 fire

The company was awarded the contract to reconstruct the building as close to the original as possible.

The Project is situated to the North of the Test Valley in Hampshire County in Southern England on the banks of the beautiful River Test, famous for trout fly fishing and “gin-clear waters.” The original waterwheel powered a grain mill. It was later converted to paper production, and even later housed a generator serving the nearby Manor House. Unfortunately, the original structure was completely destroyed by fire in early 2018.

At 21 metres (68.8’) long and 5.7 metres (18.7’) wide, the main structure is situated on a small island created by a man-made diversion in the River Test. The river flows from the north and is then diverted via a sluice gate to the right. The river then widens into a pool and bubbles quickly along the west side of the building. The diversion along the east flank drives the turbine, and passes underneath a wing that links the main structure back to the existing dwelling and also houses the turbine and mill workings. 

Historical & Structural Considerations

The original building was “listed” with the Historic Buildings and Monuments Commission for England confirming the historical importance of the building on the one hand while placing restrictions on how any work to the building can be performed on the other. What remained of the original building after the fire was still subject to the Commission’s rules and regulations, of course. It once featured shorter posts sitting on top of a brick wall from approximately first floor height. In the wake of the fire the surviving outer brick walls were deemed too structurally unsound to bear a load – however, due to the walls being “protected” under UK law, they had to be preserved. To get around this issue we installed two outer plates running around the perimeter of the building with the lower of the two (D – below drawing) supported on metal brackets (C) connected to the back of the timber Jowl posts (B) by lag bolts. The full weight of these two plates, as well as the softwood stud wall with conventional insulation and weatherboarding is carried by these brackets transferring the load to the jowl posts (B).

A detail drawing (drawn by myself) of the steel bracket, showing how load was removed from the fragile existing wall. The drawing also explains the interplay between our frame and the other elements in the building.

Design & Construction Details

Framing work started in July 2019 with a team of eight carpenters framing the bulk of the structure over a period of five weeks in workshops off-site. A team of four transported the fabricated components of the timber frame to the jobsite, assembled and raised the frame, framed the hips and valleys, then fitted the common rafters and cut and assembled the jack rafters.   

Constructed entirely from European green oak, the structural frame is very utilitarian by design and lacks the aesthetic details like the curved braces typical in many historic timber structures in the UK. Nonetheless, it has some nice detailing that might not be obvious at first glance. 

The main posts (wooden structural columns) are mostly jowl posts (aka “gunstock posts”) that flare at the top with tenons that fit into both the top plate (beam running along the top of and connecting the exterior posts) the column and tie beam. Historically, jowl posts were cut from the flaring grain of the base of a tree. These butts were often quartered and each post placed in the building adjacent to its sibling. I believe that this is a similarity historic English carpentry shares with its Japanese counterpart.

Here you can see the cross frame construction 

The dominant style of cross frame (or bent in North America) features a bridging beam (the large beam that spans the first floor and carries the common joists), a tie beam which spans the top plates. This beam stops the wall frames from spreading under the load from the roof. And then a simple truss design consisting of two vertical studs and an upper collar with short stub ties jointed horizontally between the principle rafters and studs. The purlins (the members that run the length of the roof) are ‘clasped’ between the stub tie and the principal rafter.  

The main roof frame is comprised of bridled common rafter pairs, a pre-Georgian (prior to 1714) hip gable at one end and a standard gable at the other. A pre-Georgian hip is the English name for a hip rafter that is usually square in section and canted so that one edge is in the plane of either the gable or the main roof. Hip roofs were historically framed in this way until carpentry methods changed and more of a ‘hip board’ set plumb with jacks pitched onto the sides became the preferred method of hip framing. 

The pre-Georgian hip gable. The effect of canting the hip rafter in this way means that the jack rafters pitched from the two walls have a side cut angle on top and a square cut on the edge, but the jack rafters on the gables have a more complex (and comically named!) ‘nuns crutch’ or ‘lip cut’.

The adjoining wing has a wider span and a higher apex to the main building, and the roof meets the main roof in a valley. These valleys are similarly canted into the plane of the roof like the hips. In the same way the hips produce two different jack rafter cuts so does the valley. You’ll notice that on the main building there is a square jack cut and on the linking building the jacks have a compound cut onto the valley rafter. After running into the valleys, two small hip rafters pick up the opposite slope of the main roof. All of these angles were found using the framing square. 

The junction between the wing and the main building looking back down the east wall.

The main building is split into two clear halves; one which is vaulted floor to ceiling, and the other which has two floors of joists.      

Green Oak Timbers

What sets this type of carpentry apart from other woodworking is its use of timbers that are rough-sawn and often of irregular dimensions, requiring an understanding of how to deal with imperfections. For example, timbers are often significantly out of square, and dimensions only approximate: according to the European standard allowable tolerances are +9mm ~ -3mm in section. 5mm of deflection per metre is also allowed. These significant irregularities complicate the carpenter’s job.

Moisture contents can be in excess of 60% in fresher felled stock and during the summer months the warmer weather can cause problems with drying and shrinkage – we often keep our stacks covered with hessian cloth in an effort to shade the timbers and reduce warpage and cracking. 

Timber framing using this challenging material teaches a carpenter much about the nature of wood as a living thing, the characteristics of the timbers, how they are likely to behave and what can be asked of them.  

The Layout Process

Carpenters have developed various layout systems over many centuries to overcome the difficulties of working with irregular timbers. In my company we use lofting, for example. According to this method, we draw out entire layups on the floor and align the outside edges of each member to these lines with any sectional irregularities placed on the inside of the building, whilst any crowning (deflection or bowing) is oriented upwards and outwards.

Once the layout is drawn full-scale on the lofting floor, the timbers are placed on blocks in alignment with their corresponding grid lines on the floor. The various members are then laid one over the other so carpenters can accurately mark out lengths and scribe the shoulders of the joints using levels and plumb bobs. 

The plumb bob is an ancient tool that you are doubtless familiar with – its importance in carpentry cannot be overstated. Plumb bob scribing, or ‘scribe rule’ layout, is a difficult thing to describe without actually seeing it done. What it boils down to is using a perfect reference in a less than perfect situation. By sighting down the plane of the timber by eye and comparing it at the same time with a plumb line a carpenter can gauge to what degree that face is out of plumb and then accurately replicate that plane on the shoulder of the intersecting timber. The shoulders of tenons and widths of mortices are carefully marked using this technique.

Once a frame is cut and fitted back together, a plumb bob can be used to accurately transfer and mark additional details up from the floor. In the case of this watermill I used a plumb bob to mark the theoretical positions of the purlin housings on each truss. The result was that, regardless of the amount of deflection or variation in thickness of each principal rafter, the purlin housing was maintained in a consistent level position down the entire length of the building.

A plumb bob being used to mark the principal rafter to tie beam joint. On the floor you can see the layout lines. We mark out each individual frame in a building full size on the floor with chalk lines, and then set up the timbers to those lines. This plumb bob belonged to my great grandfather who was also a carpenter. 

Frames are generally made up of wall frames (running the length of a building) and cross frames (spanning a building). Many of the timbers are therefore used repeatedly in multiple layups. In the case of main posts they are first framed into the exterior walls of a building. Once the walls are completed they are framed in the ‘cross frame layups’. To ensure that the posts return to the right height and rotation that they were in during their previous layups, we use scratched datums (often a set distance from the top of top plate) and rotation marks that allow us to wedge the timber to return it to plumb or level. 

Ensuring that a designated point on each timber is plumb and level is essential, particularly for those in multiple layups. It guarantees that a timber has been returned to the correct plane each time it is fitted up so that when it is stood up and connected to multiple beams, the rotation of each individual shoulder scribe is correct.   

Once the bulk of the main structure is framed we laid-up floor joist and ‘cogged’ the tie beams into the top plates. Traditionally tie beams were dovetailed into the plates but because the shrinkage of dovetails (green oak, remember) tends to cause the building to spread, it is now more common to see a simple cog used. A cog also slightly outperforms a dovetail in green timber when under tension.

Assembly and Erection at the Job Site

The building enclosed two concrete pads differing in elevation by about 200mm (8”). The base of each post therefore was designed to accommodate this change maintaining the design elevation of the building. This and other variables made laying-out of the building one of the most challenging I have ever been involved in.


This photo shows the “jowl posts” and the boom of the spider crane as assembly work is underway.

The only access to the site was a track through a field at the rear of the building and a small trackway and bridge over the river too narrow for a mobile crane to cross. The solution we employed was to bring in and set up a small spider crane in various places inside the building. The limitations of this machine required us to be very methodical about the assembly sequencing to ensure we didn’t obstruct subsequent lifts. 

Space was at a premium. Without a large area to unload the piles of timber, we had to unload the timbers and other materials in the field behind the property and then use a remote-controlled tracked carrier to ferry timber across the narrow access bridge.  

And, to throw one more element into the mix, the river is an extremely well-protected ‘Site of Specific Scientific Interest’, meaning we had to be very careful when cutting roof members to prevent sawdust from drifting into the water course. The scaffolders installed netting around the entire perimeter to prevent anything from falling from the scaffold. We also did the majority of our cutting away from the edge of the scaffold on a plywood deck we laid on the joists.

As the building began to take shape its scale became more apparent. At nearly nine meters high, it’s an impressive structure. 

Lessons Learned

I took away a lot of lessons from this building project such as managing levels on-site, and the importance of every trade singing off the same song sheet, as it were.

We had issues with the initial layout of the structure as it became clear that the structural steel that effectively served as the starting point for everything above it had not been installed at the correct elevation. The work was delayed while we sorted out this problem.

I also learned valuable lessons about effective joint placement. Because of the space constraints mentioned above, we were forced to erect the structure by lifting and placing each cross frame and then linking it back with its purlins. However, because the scarf joint landed on the wrong side of each truss, every time we craned a purlin into position, it was left temporarily unsupported at one end. These decisions were admittedly made early on before any proper site visits were made. A proper method statement was in place, of course, but the experience taught me that starting with the end in mind is important when planning.

I hope that you, Gentle Reader, gained some insight into the work that I am involved with and found it an interesting read. If you would like further information about historic timber framing in the UK, I recommend a small book titled Discovering Timber Framed Buildings by Richard Harris. 

– Gavin Sollars

Gavin Sollars hard at work

Thank you for your reading this article. It is rare to find a craftsman like Gavin with the skills and inclination to write about his work and a willingness to share it freely with others. Gavin did not write this to promote his company, but if you like this sort of thing as much as we do, please visit his company’s website and sign up for their newsletter.

In the next post in this series Gavin will outline the construction of the roof frame. Please stay tuned.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google or incompetent facebook and so won’t sell, share, or profitably “misplace” your information. Stick a needle in my eye.

https://covingtonandsons.com/2020/09/12/timber-frame-water-mill-reconstruction-project-uk-part-2-framing-the-roof/

Other Posts in Timber Frame Water Mill Reconstruction Project Series

Part 2 – Framing the Roof

The Sewari Kerf

If the only tool you have is a hammer, it’s hard to eat spaghetti

The David Allen

You may have noticed sawkerfs cut into the sides of the peeled cedar logs in the pictures in my earlier post about Sotomaru nomi and wondered “what the heck!?” I know that was my reaction the first time I saw similar slits many years ago.

“Sewari Kerf” sounds a bit like the phrase for hello in Thai, but trust me, I know the difference. “Sewari” 背割りtranslates from Japanese to “back split.” Nothing to do with drafty pants.

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Three peeled cedar logs joined for a structural frame. Oriented upside down in this photo. Notice the sewari kerfs and the minor cracking. This degree of cracking is acceptable.

You will also notice some narrow cracks in the peeled logs in the photo above. These are natural shrinkage cracks that always occur in timbers that contain the tree’s heart. If sewari had not been cut into the peeled cedar logs in the photos above, the cracking would not be hairline, but would be as wide and wandering and ugly as a politician’s morals.

A sewari kerf provides a predetermined location for shrinkage stresses to collect resulting in a more attractive and structurally sound post or beam. It also makes it possible to use these shiny peeled cedar posts and beams with less waste while achieving a more refined, orderly, reliable appearance.

Allow me to digress a bit while the ink dries.

The Japanese consumer places high value on uniformity of appearance even in natural materials. This is also why Japanese ladies will pay $120 for a perfect musk melon as a gift for someone knowing it won’t taste any better than a less-beautiful but still expensive $20 melon. Both giver and receiver understand and appreciate the sentiment inherent in such a gift beyond the melon’s taste.

A Father’s Day gift in a wooden box
 (102058)
Peeled cedar logs awaiting purchase at the Meibokuya warehouse. These exposed structural timbers are expensive and will be wrapped in foam and cardboard and plastic before shipping.

The point: A natural product is made to look more uniformly natural by eliminating all natural defects. Makes perfect sense, right? Welcome to Japan.

Another aspect of this cultural peculiarity can be seen most in the traditional Japanese garden, if you have eyes to see it. Tremendous time and effort and money is spent constructing and maintaining a miniature representation of the natural universe in a small space. In this case, not uniformity but exaggerated naturalness is the goal. While the ostensible goal is the appearance of natural growth and random placement of features, there is not a single natural or random thing to be found in a Japanese garden, except perhaps the water in the pond. A beautiful art form to be sure. A triumph of design and patience. But about as natural as most movie actresses nowadays.

Kutsura Rikyu Garden

The sewari kerf too is not natural, but it helps nature appear both more natural and more uniform. It is also better for the environment. Did someone just say “Poppycock?” Ah. In that case, let us reason together, Gentle Reader.

The sewari makes it possible to cut square posts and beams from smaller diameter trees at less cost and with less waste. Indeed, without the sewari, many millions of small trees that would otherwise be clear-cut to make room for roads, infrastructure, and development, then chipped and tossed aside on the forest floors of Japan to return to the soil and atmosphere, can instead be used for construction lumber.

This wasteful activity is common throughout the entire world and has a tremendously harmful impact on the atmosphere, soil erosion, and water quality. Sewari is an environmentally-friendly way to make more efficient use of the world’s most environmentally-friendly building material.

Please encourage wood producers and governments in your area to develop and employ better ways to use and maintain forests, because neither thoughtless harvesting focused solely on profits, nor abandoning forests to burn and rot and release particulate and chemical contaminants into the atmosphere and destroy animals and their habitats in the process, is responsible stewardship. We need the building materials, oxygen, and carbon dioxide entrapment capabilities of forests now more than ever. Bambi needs a home and dinner too.

I see the ink has dried so I will step down from my soapbox now (Oops, I almost tripped and broke my fool neck!).

Back to the subject of this post, please take a gander at the photos below of two square construction-grade Akita Cedar posts, both with hearts in their centers. The one on the left does not have a sewari cut, but it does have a nasty collection of shrinkage cracks. Ugly, oh sooo ugly. The one on the far right has a sewari cut, but only a couple of tiny shrinkage cracks. If you had a choice, which one would you buy? Which one do you think is more dimensionally stable? Which one is a more efficient use of natural resources?

img_7113
A beautiful Hinoki post with sewari cut and dimensioned to final width and thicknes and marked with location and orientation in the building. Notice how the kerf is narrow near the center and widens towards the timber’s exterior. This began as a simple sawcut with parallel sides, but as the wood dried and shrunk, the kerf spread into a V shape. The timber’s dimensions distorted accordingly, so this timber was trued to this final dimension after the shrinkage and internal stresses calmed down.

Japanese building codes, especially those governing wooden construction, have changed a great deal since the Great Hanshin Earthquake of 1995 mandating metal connectors in tension loading, and metal plates spanning many connections in wooden structural frames. To accomodate the sewari kerf, manufacturers of these structural connectors have developed extra-wide plates that span the kerf, with screws and nail holes offset from the centerline. The point I am trying to make in my meandering way is that sewari is now an integral but hidden part of public and private life in Japan.

Perhaps the sewari kerf looks unsightly. In the case of posts, the carpenter will orient it away from view as far as is reasonable. In the case of beams, he will orient the kerf upwards out of sight.

Sometimes, after the wood has reached equilibrium moisture content and internal shrinkage stresses have calmed down, the carpenter will glue a strip of wood into the sewari kerf to fill it. Sometimes this strip makes the member look better, sometimes it makes it look worse, especially when it pops out and flops around. What do you think?

In the top left-hand image a sawkerf is made in wet wood. As the wood shrinks, the kerf opens and the walls inside the kerf often develop a curvature. These surfaces must be trimmed straight after the wood reaches equilibrium moisture content. A wedge-shape strip of wood is then glued into the kerf. All four sides of the wood are then trued. This is an extreme example.
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リフォーム改修用語 背割り埋め

In conclusion, I would like to add a few points of clarification and a real-world example from my long-list of screw-ups.

Sewari doesn’t usually add strength, but it makes it possible to use less than ideal timbers, and to process those timbers, including reducing the moisture content to allowable limits, in a shorter period of time and with much less waste than would otherwise be possible. This is a big deal if you care about conservation of natural resources. It’s also a big deal if you are concerned about the cost of materials.

So long as the kerf can be oriented away from view, the appearance of timbers with sewari is a heck of a lot better than those without. And have you ever noticed how customers will look aghast at wandering, gradually widening shrinkage cracks in a large timber post or beam imagining that it will cause the member to eventually fail? Of course you have.

I did one job in Nevada, the driest State in the USA, using many large and long square timber posts that developed shrinkage cracks after they were installed. The cracks alarmed the Client so badly they insisted they would not occupy the building unless we installed metal straps at three heights around the posts to ensure they wouldn’t explode, when in truth the timbers were not expanding but rather shrinking, and the cracks did not impact the posts’s strength or resistance to buckling to any significant degree.

But if we had cut a sewari kerf into those posts immediately when they arrived at the hot dry desert jobsite, the amount of shrinkage would not have been less, but that shrinkage would have concentrated at the kerf and not caused the Client to make illogical, pointless and expensive demands. On the other hand, if cosmetics had been a priority, the Client would have been right to object to those ugly cracks, not that straps would have made any difference.

So I put it to you, Gentle Reader, did we save money on that job by not taking the time to cut sewari kerfs and consequently being forced to spend money and time fabricating and installing silly metal straps to resolve the Client’s complaints later, invalid though they may have been? I think not.

Go forth and do better, my son!

YMHOS

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A well-managed cedar forest in Japan

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A Cool Coat

A few weeks ago I posted an article about seismic dampers used on a high-rise building currently under construction near my office in Marunouchi Tokyo (a 3 minute walk from Tokyo Station). I pass this same jobsite on foot several times a week and take the occasional snapshot. I have other construction sites ongoing, but no high-rise buildings right now, and none that non-disclosure agreements will allow me to share with you. So this is a good opportunity to introduce you to some lesser-known details about major construction work in Tokyo as seen from the sidewalk without risk of offending any clients.

Please notice the gentleman in the orange uniform and big boots in the picture above. I have never met him before, but judging by the color of his uniform, he’s an employee with Obayashi Corporation, one of Japan’s largest and arguably most competent general contractors. I have done a lot of work with this company and respect it a great deal.

Sir Norman Foster, a famous British architect and the designer of Apple’s Campus 2 in Cupertino, California once said that Obayashi Corp is the world’s best general contractor. I tend to agree. And I say this as someone that used to work for two of Obayashi’s competitors in Japan, and who has also worked with many other contractors around the world. If you have visited the Boulder Dam near Las Vegas, Nevada recently, you probably drove over Obayashi’s bridge spanning the gorge.

Anyway, please notice that this erstwhile young man is he wearing what looks like a thick coat all puffed up like a marshmallow on a sunny day in mid-August in 37℃ (98°F) temperatures in the shade and 76% relative humidity? Is he loco, Cisco?

Setting aside the somewhat inelegant safety boots and rolled trouser cuffs which do not help the fashion statement his ensemble is making, you will notice a round white grill on his coat near his elbow. There is an identical grill on the opposite side of the coat you can’t see.

If you haven’t already guessed, the two round grills are actually battery-powered fans pulling outside air into the coat and pushing it out at his collar and wrists cooling our young contractor as he labors diligently in the heat.

Makita tool cordless fan jacket
A two-fan cool coat

These “fan coats” are very popular in Japan. They can make a big difference so long as one can perspire adequately and are credited with saving many construction workers from heat stroke and even death in hot months.

They also come in kiddie sizes and many colors.

Makita makes a “Cordless Fan Jacket” that is sold on Amazon overseas for a lot more than it costs in Japan. Instead of two fans, it has a single fan at the back. I have not used the Makita product and can’t endorse it.

The Makita Cordless Fan Jacket. Notice the high, stiff collar directing moving air over his neck for better cooling, and the fan unit at his back. The cord is leading to the angle grinder he is using, not to the fan.

I hope the weather in your neck of the woods is always balmy with cool breezes in summer so a coat like this is never useful. In the meantime, I’m just waiting for someone to develop steel-toed boots with cooling fans. (ツ)

YMHOS

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Seismic Damping

The more one gardens, the more one learns; And the more one learns, the more one realizes how little one knows.

Vita Sackville-West

This post is definitely different from my previous ones. It will deal with buildings and earthquakes. It has nothing to do with wood or woodworking tools.

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Toranomon Hills Business Tower (foreground)

In my day job I am an executive with a large international Real Estate and Construction Project Management company in Tokyo, Japan. Without going into details that might violate non-disclosure agreements, my job involves managing all aspects of real estate acquisition and leasing, as well as the design, procurement, and construction of commercial and industrial projects. Mostly for non-Japanese Clients.

The photo above is one project I am involved in on behalf of a Client.

Tokyo is an expensive place to set up operations, and the real estate and construction processes are especially confusing for foreign companies. Ergo, the need for me and my teams.

My educational background is structural engineering, focused on seismic-resistant design. All of my Clients are very concerned about the earthquakes Tokyo experiences almost daily. There will be several magnitude 4~5 quakes here each year. This tends to keep people focused.

My point is that earthquakes are a constant threat taken seriously and for good reason. Accordingly, to one degree or another as building codes and Owners require, all buildings incorporate aseismic design features.

I have worked on buildings with expensive full-blown base isolation using rubber bridge bearings and hydraulic dampers similar to giant automotive shock absorbers, and other systems designed to dissipate damaging earthquake forces, but what I would like to show you today is a “slip-joint brace damper” just installed at a building near my office located in Marunouchi near the Imperial Palace (not the building in the perspective rendering above).

Notice how deep the beams are, and how thick the steel is. Although they don’t show up well in the photo, the columns too are massive. Much heavier than is typical in Western structures. I love Japanese structural steel!

Slip-joint Brace Dampers (white), Tokyo

I am not involved in this high-rise building, but a contractor I have used in the past named Obayashi Corporation 大林組 is the General Contractor. I was able to snap this picture of Obayashi’s jobsite while walking to my office from the subway station last week during a rare moment when the front gate was open and nothing was in the way.

The white columns and diagonal braces are the key to this seismic damping system.

The white paint is a fire-resistant intumescent coating designed to protect the steel from heat during a fire. Structural steel is very weak when exposed to fire, much more so than wood or concrete, so this sort of protection, while expensive, is necessary. The rest of the structural steel will be sprayed with a thicker, less-expensive and less-durable fire-resistant coating of one variety or another.

The diagonal braces in the photo are basically two steel plates bolted together face to face. The bolt holes are slotted to allow the bolts and plates to slip past each other when subjected to a certain amount of force.

The plates and bolts are contained in a steel pipe filled with high-friction oil to prevent the brace from buckling, prevent corrosion, and ensure the coefficient of friction between the plates/bolts remains constant for many decades in the future.

As the ground moves during an earthquake, the building moves with it, and the structural steel sways. The rectangular opening framed by connected beams and columns changes shape, becoming longer or shorter in the diagonal directions. Braces resist this “racking” movement.

As the plates and bolts in these dampers slip past each other, a great deal of friction is created converting the earthquake’s energy to heat, slowing down the racking motion, and controlling the harmonic vibration of the entire building.

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Although fixed-length braces are common in lighter, shorter structural frames, they are not usually a good thing in large structural steel frames because they tend to behave erratically and fail suddenly. This can be inconvenient.

The steel frame must be made strong enough without fixed-length bracing to absorb these forces without failing anyway to make a reliable structure. But if the frequency of the building’s movement back and forth and side to side begins to match that of the ground, then something called “resonance” can occur potentially doubling the forces acting on the building, forces powerful enough to suddenly and violently bend, break and topple the building. This can be inconvenient.

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The center image employs the damping braces as in the 2nd photo above.

An alternative to this sort of damping brace system is the more expensive “Base Isolation System”

So why would anyone use an expensive system like base isolation?

Base isolation allows the entire building, from its base up, to move opposite the ground motion in the horizontal direction, reducing the induced sway, racking, and damage to its interior and systems and equipment stored inside. This level of protection is necessary if the building must continue to function uninterrupted immediately after a large earthquake. Hospitals, R&D centers, Data Centers and other sensitive buildings with lots of expensive equipment that must be kept running no matter what are often worth the cost of base isolation systems.

But in the case of an office building like the one in the photo, the owner decided some interior damage, and the business interruption repairs would entail after the earthquake, would be acceptable.

The photos below show two components of the typical base-isolation system.

Base isolation bearings being tested. Very stiff in the vertical direction, but flexible in the horizontal direction. Two bearings are being tested in this photo, but they are never stacked like this in actual installations
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Hydraulic damper combined with base isolation bearings in the background to form a base-isolation system. The building’s entire weight is supported on these bearings. The dampers keep the building’s movement from getting out-of-hand, like shock absorbers on an automobile.

I hope you found this post interesting. Let me know if you want to see more stuff like this.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” Your information will remain confidential (we’re not evil Google or incompetent facebook).