I have a covered patio, the material looks almost like a sound insulation material and over the top of that is rolled asphalt roofing. I want to know what that insulation material is that's underneath so I can go out and do a little research on it. I have tried, roof decking material, compressed roof decking material, sound proofing material. Please, someone must know what that stuff is called. It's used a lot of places where it is hot and not too rainy, like southern ca, ariz, Nevada etc.

The material looks like it is compressed cardboard [just looks like that] one side is brown, the other white, it seems to be about 4 inches thick and 24" wide, and I can't get the length of each section until I take off the rolled asphalt roofing. I've seen something that looks similar on walls, kind of like sound board which is compressed and painted white on one side. I'd appreciate any info on this material. Thanks.

Ruth

How about a picture.

How about a picture.

Good idea. Duh, not thinking clearly that's for sure. This is the 'inside' of the patio roof, the joist are 4x6x 14 ft. what you see is the actual 'decking' material, the part that shows inside the patio. It is on top of those 2x6 and there is no plywood or any kind of wook decking, only that material you see which then has rolled asphalt roofing over it. Hope you can get an idea. Thank for any suggestions.

It looks like the old excelsior based decking. They used compressed excelsior with lightweight cement and autoclaved it. Used to make it in Woodbine, GA
Howard Johnson Motels had roof decks like that.