Expert: James Ball - 12/20/2008

Question
QUESTION: What causes the trimble to have cracks?
How is it replaced?And how do you replace the morter at the end of the trimble on the inside at the flue/
Thank you
Lynwood

ANSWER: Hello Lynwood, cracks can be caused by wear and tear, age, and even from original installation. to replace it you would need to remove it and install a new one ( a mason can do this) but if the thimble is cracked it is more than likely there is damage to other areas of the chimney system and might need to be relined. I would 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.
James

---------- FOLLOW-UP ----------

QUESTION: I plan on replacing it myself.
What kind of mortar do you use?
I was told to have the thimble flush with the flue liner on the inside.Any added help would be appreciated.
Thank you!

Answer
Welcome back Lynwood, did you have a certified sweep take a first hand look? its not just as easy as "I want to replace it my self" if the vertical tile that it connects to is not cut correctly then it will need to be relined. get the certified sweep in there. saving money if great but if not done right it can be very dangers. even worse than what you started with. have it looked at.
James