I'm dealing with a roofing situation that seems unusual. The roofers stripped the old roof down to the rafters, then covered everything with plastic sheeting overnight due to rain in the Pacific Northwest. Now they're suggesting putting the new plywood roof decking directly over this plastic. I'm not sure if this is wise or if it could cause issues. Anyone with roofing experience have thoughts on this?
3 Answers
Honestly, that sounds like a recipe for disaster. Plastic sheets can trap moisture underneath, leading to condensation, mold, and potential structural damage over time. Roof spaces need to breathe to keep things dry, and using plastic like that might ruin the roof's effectiveness.
Without a question, installing plywood over plastic is risky. That plastic will trap moisture, and mold could become a future problem. If the roof has vents, you definitely don’t want to block them with a layer of plastic. You might want to get a second opinion from a different roofer.
I feel like roofers should know better than to ask that kind of question. It's pretty unconventional, and if they think it's okay, it raises some red flags. They should probably just remove the plastic before putting down the plywood to avoid any moisture issues later on.
Exactly! Typical roof construction avoids using plastic sheeting like that because it prevents proper airflow. I’d definitely raise concerns with the roofers if I were you.