Is it possible to go over 1 layer roof that is tar and gravel with insulation board and rubber? It is 12 squares not big. Have mainly done new roofs but the way things are need to take on re-roofs and tear offs to stay afloat. Thanks any advice is much appreciated.
As long as any wet material and the flashings are removed it will be fine. I suggest at least 1" iso although a thinner wood fiber will work. The iso will make the roof look like you went over a new deck compared to a thinner fiber board material.
hell if your going to go over a bur gravel roof.
then spf foam or coating systems can work.
whatever you do get all the rock off.
get it clean.
If you fasten the iso over the bur just get the loose gravel off and go over the rest. It doesn’t affect anything as long as its not between the epdm and the iso.
You probably will do this, but I would sure do a core sample first. Get the correct size fastener to hold my deck material down.
I had a BUR with Gravel, did a core sample and it ended up being a gypcrete over metal for substrate. I passed on the spud and fastening of a new deck board.
I agree with bornaroofer, I wouldn’t have a problem with it if it was cleaned off good enough.