John, I love how you turned my (in)experience into a really good lesson. I should know better, of course, too, but still I didn't recognize any warning signals lurking in the bushes. This was a front-and-center situation, and not really off-the-shelf. I didn't write the full story...
First, we had a really great barn guy helping with the guts of the columns and porch framing, and I believe he did just what you describe, searching his sawmill and lumber sources for the best wood for reconstructing the concealed framing. He prepped the wood with Termin8 where it came in contact with masonry in the ground and where the new decking would touch it.
Next we ordered custom milled, straight-grain fir in 5/4 thickness for the new T&G deck. This took months to arrive from California, but it was beautiful, except for where it was damaged in shipment. The local lumberyard let us sort through the stock to select only those boards that were not damaged, as we had to use each piece full length. The decking was installed with continuous boards under each column, except for the 8 x 8s poking through.
Two of the bases were original and had only to be shored up until the deck was installed. Wood lath was used to "ventilate" the cavity on the deck under each column. Two of the bases were fabricated new by a local woodworker in his shop on the west side of town. He had to build a special super-large lathe to turn the bases, once they were built up from new wood. We used the pine he suggested and never really discussed options, or whether he could have turned the bases in the much harder mahogany, let along ipe. His shop conditions and experience gave me confidence that he was helping us make the best choice. They looked good when they were installed.
It's now been six years, and the first sign of trouble has appeared as a small area of rotted wood where the two halves were butted together to fit around the 8 x 8 columns, and held in place with cinched straps until the glue set. No sealer was applied at the butt joints, and I'm not sure what kind of glue or epoxy was used, but we use the Gougeon Brothers' West System for most repairs, and likely for the epoxy, as it is local and works great. In six years' time, the butt seam has slightly opened and rainwater getting into the joint has been the source of trouble. Contributing to the problem is rainwater overflowing the gutter or blowing onto the base and finding any weak spot, crack, or split to penetrate the assembly. This corner has historically been a source of water infiltration due to the weather exposure, and I didn't do anything to counter this inherent flaw in designing the repairs.
We all try to make good decisions, find credible sources of information, and depend on the expertise and experience of highly skilled trades. When there is a weakness, water has a way of infiltrating the best of intentions and expertise.
Since I can't upload photos, I hope this narrative is clear enough to evoke a visual impression.
Quinn Evans Architects
Ilene R. Tyler
d 734 926 0407
------------------------------
Date: Fri, 28 Oct 2011 10:06:23 -0400
From: John Leeke <[log in to unmask]>
Subject: Maghonanany
Ilene wonders, "If someone could now tell me why I used conventional,
off-the-shelf white pine six years ago to my replace rotted column bases
that were originally old-growth Michigan white pine, I'd like to know.
Bad decision...I knew better, but I went with what seemed logical and
convenient at the time.<<
I have been trying to figure this out too, and simply specifying or
selecting mahogany is not the answer. In this past year I have seen two
cases where mahogany column plinths have rotted out, one they were
installed in the 1970s, and the other in the late 1990s. So, like with
most other exterior wood, long service life depends on the knowledge of
the woodworker to select the good piece of wood, and not on the simple
specification of a species.
Unfortunately, as we now know, you used an "off-the-shelf" product that
was not actually a piece of wood. It was labeled wood, it looked like
wood, a judge and jury would think it was wood, but it was not actually
wood. It WAS a wood-like product, designed for just one purpose: to sell
and get your money. The corporation that made and sold that product does
not give one whit about your columns or your fine old house. During the
last ten or twenty years the corporations have changed the definition of
the word wood, so that the definition does not included anything about
the durability or suitability of their wood-like products for any
specific purpose, or in fact, any purpose at all. How do they get us to
buy their wood-like product? You state the answer to this in your story:
it is by making it "convenient."
This past few months I have been trying to figure out the "convenience"
thing. Convenience seems to be a big part of the wool that the
corporations pull over our eyes to hoodwink us into buying their
disposable products, whether it is a kleenex, a replacement window or a
wood-like product.
So, how do you get a piece of real wood? For starters don't try to buy
it "off-the-shelf" and don't expect to do it conveniently. You will have
to go out of the way, and around the barn three times to get it. I get
my real wood by visiting the people I know at the sawmill, and at the
specialty hardwood dealer. Occasionally I can find a piece of real wood
at my local lumber yard, but I may have to go there three times and go
through two stacks of lumber to get it--not convenient, but highly
effective. How do I know real wood when I see it? It has 15 to 20 or
more growth rings per inch, it has more heartwood than sapwood, it has
vertical-grain, or at least rift-grain along the edges of the plank, it
has more heft (weighs more) that the other boards in the pile. Even
then, the board or plank is not perfect. As I layout my parts and cut
them out of the board I eliminate imperfections that would reduce the
performance of my parts, such as knots, flat-grain, pitch pockets,
splits and sapwood. In this way I improve the quality the wood every
time I handle and cut it.
Here is a link to my article, Mr. Baseman, on fabricating column bases
in the 9/1996 issue of Old-House Journal:
http://tinyurl.com/3qwxk68
Check out pages 2-8 of my publication Exterior Woodwork Details for more
on wood selection. Also, my Wooden Columns and Wood-Epoxy Repairs
publications could be useful.
http://www.historichomeworks.com/hhw/reports/reports.htm
John
by hammer and hand
--
**Please remember to trim posts, as requested in the Terms of Service**
To terminate puerile preservation prattling among pals and the uncoffee-ed, or to change your settings, go to:
<http://listserv.icors.org/archives/bullamanka-pinheads.html>
|