I have a home that has a timber framed non vented roof. Above the T&G roof decking 2 layers of R-Max insulation were installed. The layer over the T&G roof deck is 3″ of Multi-max FA3 polyiso board. The layer above is 3″ of R-Max nailable base polyiso board. Since installation of the insulation the roof has been very noisy when the time changes from night to day and when the sun hits and is removed from the roof by clouds. In other words the roof is very sesitive to thermal changes. The noises the roof makes are all over the diaphragm. The noises are much more than the once in a while pop that is normal with a timber framed roof. The roof has been exhibiting the same loud noises “rumbling, poping, cracking” since new. The noises are well above normal for what we would expect for a new correctly installed roof. We have tried many things to diagnose the problem. For example we have removed the metal roofing panels for a week leaving only the 2 layers of Rmax product. The roof still makes the same noises. When I remove the outer layer of the Rmax Nailable base, the noise stops! I have contacted Rmax support and notified them of the issue. I have not gotten any solution to my problem. Has anyone else experienced issues thermal related when using the Rmax products mentioned above in a multi-layered configuration similar to mine? I would like to add I am in climate zone 11 in Northern California.