Expert: Mark Sundberg - 7/8/2009

Question
I am building a tree house for my kids. I am putting up 3/8 plywood for the small rafter roof I am planning on building. I am worried about weight, that's why the 3/8 ply. I have built a substantial understructure to hold it up, but everything adds up. First of all, what type of nail should I use to apply the shingles since I'm using such thin plywood? Secondly, is there a light-weight shingle you know about that's not stratospherically expensive? The tree house is only about 8'x8'. Thank you!

Answer
Hi Gavin,

I'd suggest you look into staples rather than nails. As for light weight shingles, you might look into some of the fiberglass ones.

In reality, each 1/8" of thickness of plywood is only about 1/2 pound per square foot, so to go from 3/8" to 1/2" would only add about 72# total, assuming a 2' overhang on all four sides. Then again, if your rafters are 16" oc, the 3/8" ply should be OK, just not much good for any adults climbing around up there.