Repair or replace spalling bricks on outside of fireplace?

Question

The bricks on the outside of my fireplace are spalling. It was explained to me that the spalling occurs from the freeze-thaw cycle here in Northeast Ohio. Also, I'm wondering if it's possible that the more porous interior-only bricks were used during construction. (Home is about 30 years old.) One contractor told me this is basically a cosmetic problem, another told me it's a serious problem that needs to be addressed. The inspector who looked at this house before I bought it did not deem it a structural problem. The fireplace was wood-burning converted to gas. It's been used twice in a year. It's not really unsightly, kind of rustic looking. Just want to make sure it won't come tumbling down outside in the yard. Any thoughts?

Answer 1

Yours is not an uncommon problem and the freeze thaw cycle is the problem. Water is absorbed into the brick and when it freezes, the expansion causes the brick to pop. The type of brick is not an issue, although some types of brick are more prone to this damage than others. If your case is typical, most of the damage is in the top 3' of the chimney. Usually, the face of the brick pops off exposing what is left behind it. Once it starts, it will get progressively worse.

Frequent use of the fireplace will cause this process to speed up because of the accelleration in the frequency of the freeze thaw cycle.. You do not mention how your house or water is heated. If you heat with natural gas or fuel oil, chances are good that the furnace, and maybe the water heater, are vented using a chimney flue that is seperate fron the one in the same chimney that services the fireplace. You should be able to tell after looking at the location of the mechanicals in the basement.

Best solution is to hire the services of a bricklayer and have the affected part of the chimney rebuilt. To prevent reoccurance, spray the chimney brick with a silicone sealer every fall. It will minumize the amount of water that is absorbed by the brick. This sealer is cheap and can be applied with a garden sprayer. Another deterrent is to have a chimney cap installed. This will lessen the amount of rain and snowmelt that finds its' way down your chimney.

I feel your pain. I built my family a new home in 1976 and had to have the top 4' of the chimney rebuilt in 1992. That is when I learned the silicone trick. Fourteen years later, there is no damage whatsoever.

Good luck with your problem.

Answer 2

I'm 32years old and my dad is a bricklayer.
I've been around masonry construction all of my life. Now with that said, I assure you that unless the fireplace is noticeably, leaning(way out of plumb) you have nothing to worry about structurally. If you can see the cracks from the ground, I have 2 preventative maintenance suggestions for you. 1. A few tubes of clear silicone, a ladder, and $20 bucks for the kid down the road.
That would be the inexpensive solution for 5 to 10 yrs.
or,
2.Hire your local mason to regrout the mortar joints. Or have it completely covered with a layer of stucco.

Answer 3

One of the best ways to deal with loose or spalling bricks is to prevent them before they happen. An easy way to do that is to apply a masonry sealant designed to allow the brick to breath. - See more at: http://www.miconstruguia.com/en/spalling-brick/