Why space plywood 1/8" when sheathing a roof?
Question:if plywood is nailed tightly end to end and side to side on a roof or wall exterior B4 roofing (Metal or comp) is there a problem (L8er)? MaGoo never spaces his and I ALWAYS space mine.
Answers:
You have to leave space for expansion. If it is butted up tight and it draws moisture it will buck, causing a peak or rise under your shingles.
Roof heat up a lot under the shingles, wood expands when it heats. the space simply allows the wood to expand without putting stress on it, eliminating buckling.
This is a minor detail but I think its attention to the details that make a good builder.
The 1/8" allows for expansion in the wood as temperature and humidity change, and is most likely required by your local building code. If there isn't room for expansion, the plywood panels can push against each other, loosening nails and pulling away from the structure.
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