Q&A Crack in back of fireplace

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New Member
Staff member
Nov 27, 2012

question:I live in a 70 yr old house; at some point- the fireplace was converted *from gas to wood* and as part of this the fireplace was made smaller by the addition of bricks (presumably firebrick). These bricks are quite clear around the sides; I don't know whether the brick at the back of the fireplace is original or newer. When we opened up the fireplace to light the first fall fire- we saw a crack at the back - about 18 inches- coming up from the bottom. How serious is this? Should we not light a fire until it's fixed? Thanks! Pat Stephenson


Small cracks are usually not serious- as there is commonly more masonry behind that. To be as safe as possible- use refractory cement (available at your local masonry supply or stove shop) to patch the crack. If you are unsure of the safety of the construction- be sure to have it certified by a local chimney sweep.
Check your local Yellow pages or the link below for certified chimney sweeps.

Link: Search For Certified Sweeps
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