Expert: James Ball - 12/26/2009

Question
We have a all cinderblock house and want to install a woodstove and want to put class A pipe through wall ia a wall thimble needed or if round hole is possible does upper block layer need to be supported via. some type of header above hole to avoid joint cracks.

Answer
Hello Wilford, some Class "A" chimney require a thimble (Duratech) and some do not (ICC Excel), will the block need to be supported I would belive so, check with your local building department and read the installation instructions and follow them for the pipe you choose.
You could have a local Certified Chimney Sweep www.csia.org, there you can look up by zip code to find one near you) take a first hand look at what you have they should be able to help.
Hope this helps
James