the Carpentry Way: All Academic II                                                          

All Academic II

It's a little bit embarrassing to post up pictures of my first building, though I imagine a lot of builders would feel similarly hesitant about showing their early work. When I look at the little well pump shed now, it seems hopelessly crude and there are a million things I would do differently. However, that said, the purpose of the project was to cement together my nascent understanding of compound roof joinery, and in that regards the project was a success. As I mentioned in the previous post, after struggling with my existing notes, I found that my Japanese layout texts easier to grasp and essentially followed the methods they espoused.

The pyramidal roof - termed hō-gyō (方形) in Japanese - I made entirely in Douglas Fir, and set the common slope at 5/10. Japanese roof layout, whether in traditional measure of sun 寸 and shaku 尺 or in metric, is always done on a base-10 basis, unlike the base-12 used in N. American framing practice. Base-10 is convenient since a calculator is set up to operate on that basis, thus one can move directly from the calculator to the framing square without having to perform any extra conversion.

I connected the wall plates, keta, together at the corners using the most basic and simple joint employed for this connection in Japanese carpentry, a haunched single tenon on one piece, fitted into a single mortise on the other, and wedged. This joint is termed ko-ne-hozo-zashi (小枘差し), which means, roughly paraphrased, "little root tenon assembly":

The corner is reinforced with a diagonal brace, hi-uchi bari (the 'flint' beam) which is let into each face of the keta with a housed sliding dovetail. The rafters are received atop the keta in individual notches, which permit the rafter to remain undiminished in size at the connection. This is one of two primary methods for connecting the rafter to the plate used in Japanese carpentry (though there are several other less common methods too). I fastened the rafter to the plate using a zinc-coated deck screw.

Here's a look at the completed hō-gyō roof frame:

I chose to use an octagonal king piece at the center of the roof to receive the upper ends of the rafters, as this allowed the rafters to have a simple plumb cut. I also chose to cut the rafter and hip tails plumb for some reason, though this is more commonly done in western framing. I prefer the 90˚ end cut for common rafters in most cases.

Once the roof frame was together, I fitted the rest of the rafters, and then applied some sheathing, using job site scraps. Then I moved the roof over as a unit to the waiting shed frame:

After that, I simply popped it on top, and this is how it looked:

Besides a slight mistake I made in rafter spacing (can you see it?), the curious bracing I did on the front, which I thought looked 'neat' at the time, had a purpose of providing an exit for a garden hose connection at the pump. This form of bracing is actually rather poor, structurally speaking, and I certainly wouldn't employ it on any buildings that people were to live in and/or which take any significant roof load.

Though the building is only about 1 meter tall, I couldn't resist taking a noki-shita (under the eave) picture:

Clearly, as seen in the above picture, I had little understanding at the time of the ideal configurations for rafters in relation to perimeter fascia. Gotta start somewhere though.

The braces, which were Yellow Cedar, I then infilled with Yellow Cedar tongue and groove boards, which could be had cheap at the local building supply:

And here are a few final pictures of the building with it's roof partially complete:

Obviously, such thick roof shingles are totally inappropriate for a tiny little building like that, but it was all I had on hand and time was, as it often seems to be, running out. I actually moved out at the end of that month with the landlord agreeing to finish up the shingling. He sold the place a couple of months later. Two years after that, I was in the area and swung by to take a look to see how the little shed was aging - hopefully with some grace. When I got there I was stunned to see that the new owner had painted the entire thing lavender in color. I tightened my jaw, sat right back down in my car, and drove away in silence. Jeez...

Ya can't control what will happen to the things you make for others, all you can do is control how you make it in the first place. This little well pump shed was a great project for me and was the start of a long path of study, still on-going, in Japanese roof carpentry.

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