Started the day by sliding the south wall off of the north wall and then sheathed the north wall with 1/2 inch plywood.
I like to sheath walls lying down when possible, because it’s easier and locks in the square of the wall. We have a large tree to help us raise the wall so the extra weight isn’t an issue. The only potentially serious error is not checking square on the wall or straight on the bottom plate which is exactly what I forgot to do. I was careful to check square on the wall but spaced the bottom plate and by the time I realized my mistake we’d sheeted half the wall. A quick check revealed that I’d locked in a 1/8 dip in bottom and top plate, which isn’t a huge deal but it is opposite the natural flex of the trailer so I’m not exactly thrilled either. Nothing to do at that point but live with it. 1/8 inch over 20 feet is acceptable.
We deliberately kept the windows and doors away from the corners so we could nail on a full sheet or near full sheet of plywood. This standard feature of building construction is called a shear panel and helps the walls to resist racking loads.
Some tiny houses use 3/8 inch plywood to save weight, and we would have done the same but unfortunately the only 3/8 inch CDX available here is 3 ply which doesn’t feel strong enough to me, so we bumped up to half inch. We glued the panels on with construction adhesive for added stiffness. Nailing here is pretty standard, 2 1/2 inch ring 8d ringshanks, spaced 6 inches on the edges, 12 in the middle.
We are using 10’ sheets on the tall end of the trailer for the strongest possible continuous corners with the least amount of blocking (shear panels should be nailed on all edges). The cost of oversized sheets is nearly double but the nice thing about a tiny house is that there just aren’t that many sheets so it’s not a big deal.
– Brian
