Repair cracks in brick fireplace lining?

The chimney sweep, this year, pointed out hairline cracks inside my modular fireplace. He explained that the brick is an inner lining and that there is a metal outer lining outside them. He said that it was not something that needed to be replaced immediately, but that it should be done before next season. The replacement cost is upward of $400. Is that worth it, or is there a high heat mortar or spackle that will be able to repair what's there?

Thanks for any input.

 

The firebox of course takes the brunt of the fires' heat and it requires some special attention. The firebrick can take the heat pretty well, but the fireclay joints will fail in time from the constant expansion and contraction. In a fireplace without a chimney cover, the rain water will also pool on the smoke shelf, mix with the soot behind the damper, and form an acidic slurry that seeps into the fireback destroying the mortar joints. These joints must be kept in good repair with a high temperature refractory mortar to insure the fire is contained.

FIREPLACES. CHIMNEY SAFETY INSTITUTE OF AMERICA. Retrieved 06 December 2002. http://www.csia.org/home/fireplce.html

Refractory mortar is usually available at a local hearth and fireplace store. The deteriorated mortar between bricks should be removed and replaced.

 

Thank you. I will look for that and try to guage the feasibility of doing it myself. I appreciate the information.

--Jim

 

ZJ:

I had a similar issue w. my chimney. I have the mortar falling out between a coupld bricks at the rear of the firewell wall. I removed the old mortar (the stuff that was loose) and then used a high temp refractory "caulk" for this exact thing. Since it was a caulk it is easy to use and can "fill" cracks / spaces as opposed to a "spread on" type of refractory. Look in the caulking section of Home Depot possibly. I got mine from a local hardware place. I like to support local businesses when I can. Peace: e3 - spamman