Cracks in Brick Wall

[concaz]

I am interning at structural engineering firm. I was handed over a new project to research on. However, I have never designed or worked on brick walls in school.

Here is my question : An architect wants to create a new opening in a cracked brick wall (bearing wall).The cracks are stepped cracks (in the joints) and begin on the top of the wall exactly where the opening is to begin and end exactly on top of the opening at the end of the opening.

I am just curious as to how engineers deal with cracks in existing walls when there are new openings to be installed.

 

[SLTA]

Best start is to do a search on here on step cracks. You'll find a thousand posts. Try also repointing, cracked brick, and the like.

 

[msquared48]

If it is a stepped crack, I would be suspicious of either settlement, seismic racking, or a combo of both.

Are there other stepped cracks?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[MiketheEngineer]

Fix the footing/foundation - something is settling!!

 

[concaz]

Yes, there is an instance of stepped cracks at other end of the building.

These are the only two instances of cracks in the building.

 

[MiketheEngineer]

Now you have two places to fix!!

 

[concaz]

So if we have the footing fixed, you can create an opening anywhere or are there any standard norms that one has to follow for cracked walls?

 

[MiketheEngineer]

Assuming all things being equaland all repairs made and you have designed any needed lintels or beams - go for it. You might be able to put it where the crack is - thereby eliminating it??

 

[Ron]

Now now boys....stepped cracks do not always imply settlement. Can be a shrinkage component as well, depending on the orientation and origin of the crack.

As for the settlement. It only takes about a 1/4 of an inch differential settlement in 20 feet or so to crack a mortar joint. That small amount of settlement is not typically discernible after the fact.

The most significant problem you have with a cut-out intersecting an existing crack is to keep too many bricks from falling out when you cut the hole.

Patch the cracks first, then cut the hole.

 

[concretemasonry]

It the wall a brick bearing wall or is the brick a 3-5/8" veneer that carries no structural load?

If the opening is for a window, you may need to support any masonry above if it is veneer brick wall. If it is a true load-bearing brick wall you will have to address carrying the live and dead loads carried by the brick.

Even if it is a brick veneer, you will need to provide a lintel over the new opening to carry the dead load of any veneer masonry above and the lintel should carry beyond the opening. If it is a real load-bearing brick wall, there should be vertical steel in the cut out area that must be accounted for.

For load-bearing brick wall there should be some vertical steel on each side of the opening.

Dick



Engineer and international traveler interested in construction techniques, problems and proper design.