Tuesday, March 17, 2009

Source Material III

I recently went and looked at an interesting project possibility. It's a small Japanese building that was brought over to New England, new and in pieces, around 1930 and assembled by some Japanese carpenters. The intervening years have not been kind to the structure by any stretch, and it is in need of full rebuild today. Perhaps a bit less than 50% of the wood in the building can be salvaged - that's my guess at this point. And even with the pieces that can be salvaged, there is the tricky matter of deciding just how important it is to preserve the old, when making from new material will often be considerably cheaper just on the basis of labour costs. By the time you've chopped out the punky bits, spliced, scarfed and patched your way back to a rebuilt piece, it might well take multiples of the amount of time (=$$$) it would to cut it all from fresh. Where's the deciding line in that equation? So that's one issue to deal with.

Another revolves around authenticity. The frame of the building and all the sliding doors are made from Sugi, known as Japanese Cedar in the West, cryptomeria japonica in botanist's lingo. As usual for trees called 'cedar', Sugi is not a true cedar, though it shares the working quality of cedar in that it is relatively soft and is fairly rot resistant. It doesn't grow 'round these parts though, so then I started looking a little more into where I might get it.

That leads to an interesting little story. It seems that after the second World War, the Japanese commenced a large scale re-forestry program, and they chose to do the bulk of the replanting in Sugi as it is a widely used building material. This seems, at first glance, like it may have been a wise and practical course of action. Now, some 60-odd years on, Japan is heavily forested, and primarily in Sugi which is now of prime age for timber cutting. Sugi releases a lot of pollen in the spring, and as with any pollen, some people suffer allergies - in fact some 10% of the Japanese population suffers bad hay fever in the spring largely as a result of Sugi pollen! An unintended consequence of a reforestation program if there ever was one.

So, you'd think that with all the mature trees, the Japanese would be chopping a bunch down, which would provide plenty of building material and would even help ameliorate the hay fever sufferings of a lot of folks. But that's not happening. Why? Well, two reasons it would appear. The owners of the wood lots, which are small family-owned parcels for the most part, see the trees as valuable and are reluctant to cut them (imagine that!). Now most of us would agree that, like Merv Wilkinson at Wildwood, this is showing some astute forest management practice - treating the trees as inherently valuable and worthy of careful management. Yet, the plot thickens...

Another factor in the lack of cutting is that it is cheaper for the Japanese to obtain their wood elsewhere - it costs more in terms of labour and log prices to cut their own forest, so they- I mean gigantor companies like Mitsubishi - are busy mowing the forests of places like Indonesia, Borneo, and Sarawak down to stump wastelands. There is an irony in the fact that wise domestic forest practices in Japan can directly lead to less than wonderful practices elsewhere to supply their own market. Obviously, the Indonesians - those that 'own' the forest resource at least - would be wise to place greater value on their forest than they appear to do right now, for today's 'cheap' will equal tomorrow's 'gone' if the pace of cutting continues unabated.

So, it looks like there is a surfeit of Sugi available out of Japan, it is sustainably managed, relatively inexpensive, and it is free from tariff as far as import into the US is concerned. However, when I started thinking about it, I thought, "that's crazy, getting wood from Japan to build with over here". So I started thinking about what else I might use...

Out of the domestic N. American species, probably the pre-eminent two choices for this sort of work would be Port Orford Cedar (chamaecyparis lawsonia), not a true cedar, and Yellow Cedar (chamaecyparis nootkatensis), not a true cedar. P.O.C. suffers badly from a root fungus problem, and supplies are limited as far as the 'good stuff' is concerned. It also is a wood which, when worked, is a real strain on my bodie's immune system, and besides the constant runny nose I experience, I find the smell of the wood to be somewhat noxious after a while. Yellow Cedar is often harvested in a non-sustainable manner in B.C. - I don't know about Alaska so much, but I doubt the practices are significantly better. Both woods would come on a truck from across the continent, which seems scarcely much different, in terms of enviro-footprint, than getting Sugi from Japan shipped over on a freighter. The Sugi is harvested in a wise manner, and probably cheaper than either the P.O.C. or Yellow Cedar. Hmmm.

Yellow Cedar and P.O.C. are available by salvage, but that is a bit of a crap shoot at times, the supply is inconsistent and I have had too many hassles already with sawyers who can't cut exactly what I want. Once bitten twice shy, and I'm way past 'once bitten'. not to say I might not try that route again, however with some trepidation.

There's also Swamp Cypress, Bald Cypress and Pond Cypress from the Southern US. I don't know much about forestry practices in those places. There's salvaged Heart pine. Salvaged Chestnut from old road beds - the color would be close to the Sugi.

Well, of course there are a lot of species that might be put to good use for a timber frame like this- Black Locust, Black Cherry, Atlantic White Cedar (not a true cedar), Northern White Cedar (not a true cedar), so on and so forth. There's also Eastern Red Cedar (not a true cedar - a member of the juniper family) The 'cedars' on the Eastern seaboard are a fair bit smaller than their west coast cousins, so the material working quality will be inferior I would imagine.

I think Black locust would be an excellent choice - except for the color. The color in fact will drive a large part of the decision I suspect. If the idea is to save as much of the existing structure as possible, then the most seamless match for the old would be with Sugi from Japan - and even then it would be 10 years or so before the old and new started looking more harmonious. If I go with another wood species, then I am quite sure that the client would not be keen on the mix of timber colors, at least for those parts in view. It might work if I could confine the old wood to one place, but that might not be so workable - I don't know for certain what will be salvageable and what won't be at this point. If a true continuity of color is important to the client, then that tends to suggest replacing all the material with new, which pretty much 'does in' the idea of re-using what I can. That doesn't seem like an acceptable solution. Again, hmm....

The Black Locust is yellow-green when fresh cut, but after exposure to the sun eventually goes a sweet shade of reddish brown, a shade that would, I think, be complimentary to the Sugi. But whether the client would tolerate the look of the new building in that material, and be prepared to wait for the color shift is another question.

The client is also interested in making the structure more durable than it was in the original iteration, so this may necessitate a switch to another wood species, at least for those parts exposed to the weather.

This job is not any more than a discussion at present, but it has certainly been food for thought so far in terms of considering how to restore a building in a way that is both faithful to the original and respectful of environmental/wise use issues when you have a case like this one in which the original materials were imported. There's a lot of timber framing being done today in New England, and elsewhere, with non-native woods, like Douglas Fir for instance, which is probably the predominant wood used in North American timber framing. When people want, say, a 60' long beam, few other species can supply that requirement.

Even in cases where the original building in question is entirely of native materials, it is sometimes the case that an equivalent quality or size may be unobtainable for a faithfully-accurate restoration to take place. When the Japanese rebuilt the massive Todai Temple in Nara in the mid-1800's, they scoured the country from one end to the other and were not able to find a replacement of adequate size and quality for the ridge beam, so they ended up substituting for it with a metal truss. This truss is hidden above the drop ceiling in the structure so no one sees it, but I wonder what the choice would have been if the beam in question had been a highly visible one? Probably a re-design would have been necessitated, not and easy course of action when an iconic national treasure is involved. Where this trend points to in the future is an intriguing question, and one that I'm sure keeps some building conservation specialists up late at night. Maybe I should get together with them and we could have a big conference call for those nights when I'm not sleeping?

2 comments:

  1. I was surprised that you didn't include river-recovered "sinker" cypress as an option. As sustainably harvested as can be, and old growth stuff to boot. Of course, there is that whole non-native species thing, as well as the resultant need to truck all that stuff from Florida or Louisiana to New England, which I find really undesirable.

    Was wondering how hard black locust is on hand tools, considering its density. I am picking up a couple of timbers from a sawyer in N.J. on Friday and am curious as to what I am in for.

    Thanks again for your always interesting posts.

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  2. You should get enough wood, no matter which species, to replace everything even if you can salvage something - that way, there will be enough down to road (keep the extra in storage) as eventually, the original remainder might need replacing and you will have the matching species.
    If it were up to me, I'd go with something local and harvested in a sustainable way.

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