Originally Posted by
labman
I see OSB exposed to the weather and holding up a long time. I sheathed a tree house for my kids out of 1/4'' OSB. It held up good for 6 years before I tore it down because they were grown up. Biggest problem was the tree limbs getting bigger than the holes I cut for them. It doesn't stretch very well.
LOL Well I have a piece of half inch (or 7/16 or whatever the stuff is) that was leaning against the porch during the severe rains this spring in the hudson valley region. I figure its been maybe 6 months it is well over 3/4 now. I guess if the lumber sheds the water well, like the house or your treehouse having the sheets in the vertical position, it would hold up longer. Another example is a house I just went back toin order to add extra holiday light outlets before sheetrocking. It had been sitting for a month the rain had been coming in near the chimmny which hadn't been flashed or capped yet and the floor swelled up a lot. The hardwood floor guys had to sand it quite a bit. Funny thing is they dropped their oak down and the roof still was leaking.