Expert: James Ball - 6/29/2009

Question
I am having a cement chimmey block and clay tile chimney
built for a new wood stove. My Contractor is not joing the sections with morter or grout or anything is this acceptable?
He is just stacking them one one top of the other with only
their weight to hold them together. I do not feel good about
this situation.
Thank you in advance for your help.
Jim

Answer
Hello Jim according to NFPA 211 2006 Edition sec, 7.2.10 Fireclay Flue Liners. sec, 7.2.10.2 Liners shall be bedded one on top of the other in a medium-duty, non water soluble calcium aluminate refractory cement mix or its equivalent. sec, 7.2.10.3 Joints shall
be left smooth on the inside. Sec, 7.2.10.4 Portland cement bonded mixtures shall not be used.
also check with your local building department if no building permit was taken out then then the contractor might be in trouble and will have to fix it.
hope this helped
James


Jim thank you for the wonderful rating, I forgot to point out that if this builder cemented the tiles all the way around (back side) with cement they will began to crack when you use the fireplace. in other words the only area that should be cemented is where the they are
beaded one on top of the other and no cement on the back side this will allowing the flue to expand and contract with out cracking.
But if it is solid it will crack.
James