I dont think I can do that, the thimble doesnt reach the inner brick, it doesnt reach the backer board even thats in the pic. Theres a 3” difference. I was thinking about just cutting the backer board so its wider then the inner thimble and then running the pipe thru, will this work?Yes, a smaller hole is adequate, as long as the PV will pass thru it and align with the inner PV.
You may have modify the outside 1/2 of the thimble to make it sit flush against the outer bricks..
Just make sure the inside 1/2 also is flush against the inner bricks...
I dont think I can do that, the thimble doesnt reach the inner brick, it doesnt reach the backer board even thats in the pic
So my question is do I need to apply caulk at the joints of the vent?also I put some stove cement around the exhaust port before applying my adapter, will it be good and sealed? Also im doing my first startup, any advice?