My interior fireplace tile chipped over a year ago
Rdgina
| Posted in General Questions on
My interior fireplace tile chipped over a year ago. Now a powdery efflorescence has eaten away at it. Four tiles are now eaten up, flying off, deteriorating before my eyes. Our 1927 fireplace will flake away in a matter of time. A masonry guy inspected it.
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Sounds like you have water intrusion damaging the masonry. Does the chimney have a metal cap? What about flashing at the roof line?
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Gina,
David is right that you have to figure out where the water intrusion is coming from. Other possibilities: the fireplace footing is sitting on damp soil, or the chimney has multiple flues, one of which is used to vent an appliance that is saturating the chimney with damp flue gas that is condensing in the flue.
I'm going to attach a picture of these interior fireplace tiles crumbling away~ gina.
The exterior brick has slight efflorescence down low near ground. There is no problem with flashing or rain cap as inspected by s masonry guy. One vent is used for the fireplace insert. The other unused vent was capped off/closed at the top. Done 3 years ago. Sounds like footing on wet soil as Martin said or is there any potential problem with closing off one cap at the top? Would moisture build up in this closed up vent?
Thanks for your help.
- Gina Allen
.
If there are (or had been) gas / propane / oil fired appliances using terra cotta or brick lined flues in that chimney and the chimney is way oversized for the size of the burners, there could be damage from flue condensation. (Martin's comment in response #2). But given that the damage seems concentrated near the bottom the theory that it's ground moisture wicking seems a more likely scenario.
If convection up the now-capped flue had been a drying path for the masonry that may have masked the moisture intrusion issue, and now that that path is dramatically reduced it may be more pronounced. The drying path only hid the issue- the real solution would be to deal with the moisture at the source.
A metal chimney cap that's big enough to cover the majority of the area at the top of the chimney, and not just a small hat covering the flue for the fireplace insert) would mitigate direct rain wetting (a lot). Using a waterproofing sealer over the domed mortar chimney cap, &/or replacing a mortar dome chimney cap with a lightweight concrete (less likely to crack), perhaps with Xyprex or similar mixed in to limit wicking would help too. (I would have expected the masonry guy to have inspected the top of the chimney and perhaps suggested either or both of these solutions?)
Is the chimney on an exterior wall, or somewhere in the middle of the house?