Wednesday, September 22, 2010

Building a Sukkah - Some Pics

My prior post (from two years ago) on building a sukkah did not have pictures. I have now remedied that problem.

The most important thing about a sukkah is that it be structurally sound. You don't want it falling on guests. As noted in the earlier post, I accomplished this by bolting 2x4s together using metal L-straps to prevent racking. Here is what my basic corner joint looks like:



Note that the two 2x4s sandwich the L-strap between them, and each joint has 3 bolts. Each bolt protrudes by 1/2". So since standard 2x4s are actually 1.5" x 3.5" (don't ask), there are two "short bolts" (at the top and the left) that are 2" long (1.5" for the board, plus an extra 1/2"). There is also a longer bolt in the center that is 3.5" long (it goes through both 1.5" boards, plus an extra 1/2").

Also, each bolt has two washers.

Here is a "double" joint in the middle of the sukkah.



This is a double version of the first joint. There are actually two horizontal boards that end in the middle of the vertical board. (You can't see it from this side.) Note that in the first picture, the holes were centered on the vertical board, but in this picture, the holes are offset. I needed room for two L-straps. This takes some careful measuring. As noted in the previous post, I carefully made a template and then used it to mark all the holes.

Finally, here is a three-way corner joint. This joins three orthogonal boards.



A few things to note.

Note the marking on the right side mostly covered by the L-strap. It says "L3-R4 Down" This indicates that this is the lower board that goes from L3 (the third vertical post on the left side) to R4 (the fourth vertical post on the right side). (I have an extra vertical board on the right side to accommodate the door.) Uniquely marking each board is critically important.

There are two sets of three holes here. I had to make sure to offset them so that the bolts did not bump into each other. So I raised the board on the right by 1.5" by simply placing an small offcut from a 2x4 under the template while I marked the holes. I did that with all boards going that direction.

The joint on the left is the same as in the first picture. But the joint on the right used bolts of different lengths because two of them are going through the long size of the 2x4. So the 3 bolts are 4", 5.5", and 2". (I leave the formal proof as an exercise for the interested reader.)

* * *

One final structural point. I have two doors in the sukkah. (The sukkah is located at the corner of my house, and it blocks access from driveway to the backyard. The two doors give us that access. Here is the small door on the left, and part of the larger door on the right. Not that the doors do not have a bottom board (it is easy to trip over them). To give that side support, each side with a door has a complete square of 2x4s (top, bottom, left, and right) next to the door opening.



Here's the view from the front.



And here's the view from the inside (with a special cameo appearance by Dad, another Jew with another couple of opinions).



Note that the height of the vertical boards (7') is calibrated to the 6' height of the plastic-bamboo walls, plus 7" for the two 2x4s, plus all little extra for some space at the top and bottom. 2x4s commonly come in 8' lengths, but if I left them at 8', the extra space would raise an issue as to whether the wall is a complete wall. Also, I could attach the top bolts on a 7' vertical board without standing on a ladder, but not on an 8' board.

Finally, although none of the pictures show it, I marked the top-front-left corner of each board by making a slight bevel on top-front and top-left edges next to the top-front-left corner. So not only is each board uniquely placed, but it is easy to orient each board. I simply orient the board so that the notches are on the top-left and top-front edges.

It took a lot of careful planning and drawing to think through all the joints, to count up all the nuts and washers and bolts (in various sizes) that I needed, and to make templates, notch the boards, drill the holes, and square up each side. But it was worth it. Three years ago, two friends and I designed and built our sukkahs using the same design methods, but with slight variants in size and orientation. It was a lot of time and a lot of work. But we ended up with sukkahs that look good, are very strong, and can easily be stored. If a part gets lost or broken or damages, we can easily replace the part at the local hardware store. And most importantly, the sukkah can easily be put up and taken down; we built each sukkah in just 2 - 2.5 hours this year.

Chag sameach.

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