Insulating the inside of a flat roof - DIY Chatroom

mugwortt · 12-29-2007, 06:40 PM

I want to increase the insulation value of my roof/ceilings on the main floor of my duplex! Adding more insulation to the exterior/roof dose not incease the insulation value due to the air space between the batt insulation(in contact with the ceilings) and the roof.

I am looking at adding 1 or 2 layers of the foil/bubble wrap or foil/foam to the ceilings inside the unit. I do not want to lower the ceilings too much so thought this was a good way to go but would like to get some more info from people that know more about this kinds thing. The plan is to strap the ceilings afterward and install thin pine tongue and grove for the finished ceiling.

Any thoughts on if the foil/bubble wrap or foil/foam is a good way to go? Or are there better products out there to use?

thanks Dan mugwortt@hotmail.com

USP45 · 12-29-2007, 07:13 PM

first off the roof needs to breath. If we insulate the roof against the plywood then the roof can not breath. Any condensation will freeze to the bottom of the plywood causing rot and or mold issues. As far as the ceiling goes anything is good. Fiberglass is best in my opinion unless you want to spend some $$$ and have it sprayed with expanding foam.