PSP Shoring

I've got a line on decent pricing for 2" thick larch to use as the shoring in a planned Oehler build. I plan to put posts at no more than 6' on center. I do not have a cheap way of putting tongue and groove in or shiplap. How important do you think this is? The wood will be pretty green. I'm in Northeast PA. The soil is rocky and heavy with clay. Quite a steep angle of repose though.

Nathaniel Bouman wrote:I've got a line on decent pricing for 2" thick larch to use as the shoring in a planned Oehler build. I plan to put posts at no more than 6' on center. I do not have a cheap way of putting tongue and groove in or shiplap. How important do you think this is? The wood will be pretty green. I'm in Northeast PA. The soil is rocky and heavy with clay. Quite a steep angle of repose though.

I have an earth-covered little guest cabin that has 2x10" spruce for walls with a span between posts of about 9ft at most. The walls all slope in, so the span is greatest at bottom and narrows to about 3ft at top. The earth covering is about 1.5ft thick at the base and I do see some bowing-in on the lower planks. If they had been lapped or T&G, they'd have more stability.

It'd be great if you had enough planks to do a double thickness with staggered joints.

As the lateral pressure will be greatest near the bottom of the walls, I would suggest doubling up and lapping the planking there. You will end up with somewhat proportional strength to load: if a single thickness were sufficient at the base, it would be overkill near the top, and if just sufficient near the top it would be inadequate near the bottom.