# My chimney bricks are spalling, solutions?



## tickbitty (Sep 11, 2011)

My chimney bricks are spalling.  The brick house is 50 yrs old, the house bricks are not spalling, but the chimney is.  I had to get the front stoop rebuilt last year, but that was mostly a mortar problem not really a brick issue.
I find small 1/4" "slices" of the bricks that pop off occasonally and slide down the roof.  Is there anything that can be done with this - careful patch with cement or anything?  Or do the offending bricks have to be removed and replacements mortared in?  I can't afford a big fix.  It's a one story house, and a central chimney.
You can see a few of the bricks spalling here, there are a few more doing it now.  The top is as shown (but now there's a liner cap coming out of there and a plate)


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## jimbom (Sep 11, 2011)

The source is likely moisture.  Wet - dry cycles or more likely freeze thaw cycles.  Cut off the entry of moisture from inside, top and perhaps outside the chimney and the problem may be solved.  Don't, however, put an impervious moisture barrier on the exterior of the chimney.  Moisture inside will be trapped, collect, then turn to ice during the first freeze.


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## tickbitty (Sep 12, 2011)

Thank you.  I suspect you are right, and figure I could have the cement crown amended or expanded to help with that, or maybe some kind of plate across the top?  But is there anything that can be done for the bricks that are currently spalling or have already spalled, or will they all have to come out and be replaced/repointed? 
The chimney sweep quoted some ungodly amount to rebuild the entire thing, I won't pay that and don't really think it's all that bad yet anyway, but it does need to stop now or it will need replacing soon, I suppose.


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## jimbom (Sep 12, 2011)

My guess is once the moisture is addressed, deterioration will stop.  At that point, you could tuck point those joints that may have loosened, but the brick will be stable.  

I have the same problem on my mother's house.  Two fireplace flues.  She doesn't use the fireplaces, so I put a vinyl storm window type membrane in in the fireplace in addition to the damper.  I am trying to keep warm moist air from rising and condensing on the interior of the chimney.  So far, it seems to be working.  Next, I am getting the chisel, knocking out the motor that needs it, and redoing those joints.

Her concrete chimney cap is in good shape, but had a few fine cracks.  My first go was to seal those with silicone caulk and seal up the joints around the concrete/metal raincaps.  Didn't notice any big difference, so have gone to the condensation idea.  Her damage is on the east and north side of the chimney.  The west and south have little apparent damage.  So there is something subtle going on with temperature involved.

Tapping around up there, my opinion in my case is the spalled bricks are still sound.  Matching her bricks will be almost impossible.  So unless they are coming apart, I am going to make do with a good repair that sheds exterior water.  Hers has lasted about 60 years, so it is time for a little TLC.


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## tickbitty (Sep 12, 2011)

Thanks very much Jimbo, that's helpful.  I'm afraid I'm not a confident DIY-er with this kind of thing.  Would it be a mistake to hire a mason, or would a handyman be better you think?


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## jimbom (Sep 12, 2011)

tickbitty said:
			
		

> Thanks very much Jimbo, that's helpful.  I'm afraid I'm not a confident DIY-er with this kind of thing.  Would it be a mistake to hire a mason, or would a handyman be better you think?


  This a much harder question.  If you could get some input from your neighbors or coworkers, that would be best.  Mason or handyman - see if they will visit and give you a quote along with an idea what they propose to do.  Once you pick one, ask for references on chimney repair jobs.  Check those.  Make sure they have workmans comp and insurance.  Your homeowners policy will have guidance for you on having contractors work on your property.  A good job done here will last several decades, so consider that when evaluating the price.


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## tickbitty (Sep 12, 2011)

JimboM said:
			
		

> tickbitty said:
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Great ideas, thank you.


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## kenfsr (Sep 19, 2011)

moisture penetration into brick and concrete, freeze thaw making brick spall and delaminate, solution= clean brick and concrete to remove all dirt,mildew,laitance , etc. power wash or minimum hose off cleaner and dirt. appply clear sealer after brick is dry, 24 hrs. minimum dry time in good weather. I have used  OKON products in past as a contractor with good results. website http://www.okoninc.com/Home.asp . Hope this helps


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