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About 8 years ago I rebuilt the top 8 courses of brick on my chimney. Most of the bricks are now falling apart – sheets of brick material are coming off of the surface. The remaining original brick (also exposed to weather) is fine.
Did I get just get the wrong type of brick for the repair? Or is something else going on here?
If it is the type of brick, what should I look for this summer for the re-repair?
Thanks for your time!
AB Hawk
Replies
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Good Afternoon AB Hawk,
This may seem like an odd question to you but, describe the mortar mix you used and did you change the inside liner when you did the chimney repairs.
Regarding the bricks, you didn't use old used clay bricks by any chance from a demolished building?
*ABSounds as if the bricks you used last time were a tad pourus, ie they have taken in water and by the sounds of things have then frozen, which has caused the damage.You really need to use quite a hard brick around the chimney area. When you replace this brickwork I would either try to get bricks of the same type as those below the damaged area or a contrasting engineering brick, even in a dry climat brick can be effected by the moisture in flue gases.Good luck Martin...
*Sir,I suggest you ask your masonry supplier for their recommendation. Bricks vary from region to region, manufacturer to manufacturer. Your supplier should know the brick that are most suitable for your situation. Usually the problem is water. #1 Make sure you are using a compacted, concave joint. #2 Make sure your crown is in good shape. No cracks. Caulked expansion joint around liner. Overhang to serve as drip edge. Note: If you are putting on a new crown, put down a layer of ice and water shield (roofing membrane) under the crown. In the future, if h2o gets through the crown, membrane will not allow it to enter brickwork. #3 Get yourself a good chimney cap. I suggest one that covers the entire chimney. This will not only shed water, but keep out birds, rodents etc.buenas suerte!
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Thanks for your reply.
I used a small bag of Sakrete mortar mix.
I did NOT change the flue liner tiles; they were still in good shape and solidly attached to the remaining original chimney.
The repair bricks were brand new and of the same nominal "style" as the originals - just 15 years younger.
*Thanks for your reply.I used a small bag of Sakrete mortar mix.I did NOT change the flue liner tiles; they were still in good shape and solidly attached to the remaining original chimney.The repair bricks were brand new and of the same nominal "style" as the originals - just 15 years younger.
*Thanks for your reply.I used a small bag of Sakrete mortar mix.I did NOT change the flue liner tiles; they were still in good shape and solidly attached to the remaining original chimney.The repair bricks were brand new and of the same nominal "style" as the originals - just 15 years younger.
*Thanks for your reply.I used a small bag of Sakrete mortar mix.I did NOT change the flue liner tiles; they were still in good shape and solidly attached to the remaining original chimney.The repair bricks were brand new and of the same nominal "style" as the originals - just 15 years younger.
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Good afternoon, AB Hawk,
The reason I asked for the mortar mix is something would have had to cause the bricks to chipoff and sometimes people use a cement mix instead of a mortar mix and being stronger than the brick would cause damage to the brick.
So that part is eliminated.
The reason I asked about the flue liner as you know was obvious and seeing that you had inspected it prior to your work,
that idea is out.
The reason that I asked about the brick is not knowing the age of your house, a house made of brick that is 100 years old or so, would have brick made of very different tempers. Bricks that were not meant to be exposed would have been soft and bricks for the harshes exposures would be very hard. Had you bought bricks to match an old house and picked up some of those old bricks, the exposure to freeze thaw cycles would have chipped off exactly as you described.
That idea is out the window also.
So why is your brick chipping off? You may be right in thinking that you got a bad batch of bricks. It doesn't hurt to contact the manufacturer's quality control division, they are normally quiet good at standing behind their products. They should at the very least replace your bricks.
It is still highly unusual what is happenned to your bricks on the chimney.
In spite of your inspection, I still feel that there's a possibility that you may have a damaged flue much lower down than you inspected and excessive heat is hitting your bricks at the top where heat would be trapped. The last thing you would want would be a chimney fire.
Wish I could have been more help to you but it was a tough one to figure.
*You may wish to visit the Brick Institute's Web site (http://www.brickinfo.org/) and check their technical notes. Brick spalling is usually a matter of freezing water chipping off the brick or the mortar being harder than the brick. Sakrete, by the way, is a fairly hard mortar. If the cap didn't prevent the moisture, I'd suspect it as the problem. One way to keep outside water out and still allow inner moisture to leave is to coat the brick with a siloxane sealant. It allows water vapor to pass through, but not water droplets.
*Sir,I had no idea you used Sakrete Mortar Mix. Yow!You need to use Masonry Cement Type N, or S if you're AR, mixed with good quality sand. The reason premixed products are so cheap, imho, is because they are mostly sand and bad sand at that. Sometimes I suspect manufacturers are scrimping on the cement. Cement is of course, more expensive than sand. We only sell Sakrete Mortar Mix for quick fixes, craft projects, etc.Over and out.
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About 8 years ago I rebuilt the top 8 courses of brick on my chimney. Most of the bricks are now falling apart - sheets of brick material are coming off of the surface. The remaining original brick (also exposed to weather) is fine.
Did I get just get the wrong type of brick for the repair? Or is something else going on here?
If it is the type of brick, what should I look for this summer for the re-repair?
Thanks for your time!
AB Hawk