Vaulted ceiling popping noise
5 years ago we installed a T&G ceiling in our living room using Cedar Cyprus. Because the ceiling is vaulted we had little insulation on the outside under the shingles. To offset this I researched a product called Thermax which is a 2-inch thick polyisocyanurate rigid board insulation for interior and exterior continuous insulation made by Dow Chemical.
About 6 months after installation the ceiling would ‘pop’ and ‘creek.’ At first, I thought it was the wood expanding but after realized that is not the case. The Thermax has a foil type exterior on both sides and the 4 x 8-foot pieces fit in between full-length beams.
The order of insulation top down is:
Shingles, paper, (no plywood on this section)
Old ceiling made of 2.5 inches of T&G wood. Turtle vents were installed.
Thermax right up against on ceiling.
3 rows of 1×3 pine lengthwise
Cedar Cyprus T&G
have 2 videos to show the ceiling and popping and the second to show the construction. They are too large to upload. I am lost and would truly appreciate any solutions/suggestions.
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There are several issues here.
1. We need to know your geographical location or climate zone.
2. I don't know what "cedar cyprus" is. Cedar is a type of wood, including such species are Western red cedar and Eastern white cedar. Cypress is a different species -- notice the spelling of "cypress."
Cyprus is a country in the Mediterranean. There is a species called Cyprus cedar, but it is a rare wood that isn't found in North America.
3. Your roof assembly doesn't have much R-value -- it's probably about R-13, but the insulation layer is interrupted by your rafters, which are apparently about 3 ft. or 4 ft. on center.
I'm not sure what could be causing the noise.
By the way, you need to get rid of those turtle vents. You have an unvented roof assembly, and all those turtle vents will do is provide a pathway for rain to enter your house.