Here is the scoop. I live in a 1907 home with an walk up attic. I just finished framing the attic. I used to have a brick chimney going through my roof (for boiler, there is NO fireplace in the house). The chimney leaked like crazy cause of deterioration. A contracter came out, removed it, put in a metal stack and new liner all the way to my basement.
Fast foward back to my attic project.
I removed the brick from under the roof line since it was in pretty bad shape, leaving the flex liner exposed. I built the knee wall and now the flex line is about 3 inches from the bottom plate of the knee wall. I'm worried about heat being so close to the wood. when i turn my heat on full blast, the flex line gets warm, but I can still touch it, but after a few seconds i have to pull my hand away from heat. is there some other type of barrier i can add.
would putting cement board on the back side of the knee wall facing the liner work?