Cracking in existing masonry
Cracking in existing masonry
(OP)
There is a fairly large attachment to this long post including several pictures, a partial plan and a partial elevation view. It's an existing 4 story structure from 1950s with load bearing brick walls and concrete on bar joist framing.
There are two locations of significant cracking within the existing masonry along the west elevation of this building. This attachment shows cracking along at the south end. There is similar cracking at almost identical mirror location to the north. My goal is to determine the cause/causes of the cracking and suggest a repair procedure.
To summarize the pictures:
Existing walls are 16" multiwythe brick. This story is a partial basement. And I guess this would be my first question: I can't tell from the drawings if the brick continues below grade. Was use of brick as basement or foundation wall ever practiced? I am wondering if below grade (on the exterior face) the brick is replaced with cmu or even concrete. The gap between existing ceiling and wall (pic 2 & 4) indicates movement of the walls to the outside at the top. The wall is bowing in at the crack location (pic#1).
I did not see any expansion joints along the whole elevation and I wonder if the cracking is partially due to that.
There is also evidence of water infiltration at the roof level and I believe that is a contributing factor.
Caulking within the cracks at the exterior suggests that this cracking has been around for a while.
I have other pictures but did not want to post a very large attachment. Obviously I am requesting some insight from the participants here to help me out a bit.
There are two locations of significant cracking within the existing masonry along the west elevation of this building. This attachment shows cracking along at the south end. There is similar cracking at almost identical mirror location to the north. My goal is to determine the cause/causes of the cracking and suggest a repair procedure.
To summarize the pictures:
Existing walls are 16" multiwythe brick. This story is a partial basement. And I guess this would be my first question: I can't tell from the drawings if the brick continues below grade. Was use of brick as basement or foundation wall ever practiced? I am wondering if below grade (on the exterior face) the brick is replaced with cmu or even concrete. The gap between existing ceiling and wall (pic 2 & 4) indicates movement of the walls to the outside at the top. The wall is bowing in at the crack location (pic#1).
I did not see any expansion joints along the whole elevation and I wonder if the cracking is partially due to that.
There is also evidence of water infiltration at the roof level and I believe that is a contributing factor.
Caulking within the cracks at the exterior suggests that this cracking has been around for a while.
I have other pictures but did not want to post a very large attachment. Obviously I am requesting some insight from the participants here to help me out a bit.






RE: Cracking in existing masonry
To your question of whether brick was used below grade, my amnswer is yes it was in the latter 1800's and early 1900's in the area in which I reside (Toronto).
RE: Cracking in existing masonry
RE: Cracking in existing masonry
Thanks for the input. What did you guys think of the last picture. It appears to me that a crack occurred because of lack of control joints, then water was absorbed and masonry expanded.
RE: Cracking in existing masonry
That is a long building, so the expansion can produce large forces to resist the expansion.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Cracking in existing masonry
You are right, since the building is 60 years old, I think all the movement that had to happen took place long ago. Your comment about the expansion explains the bowing out of masonry on the few locations I noticed, that makes sense.
What sort of remedial measures would you think would be required. I was planning to reinforce both sides of the crack in the basement (pci#1) with steel angles bolted each side of the crack. I am not sure about the bowing out over the windows (last pic).
RE: Cracking in existing masonry
It is also worth to mention that I have observed a number of times on buildings that have wings, or even closed patios, and this one can be one more of them. However since the building is so old it points to some change, local excessive heating, water content change, etc.
RE: Cracking in existing masonry
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Cracking in existing masonry
RE: Cracking in existing masonry
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RE: Cracking in existing masonry
RE: Cracking in existing masonry
Could you send your info to masonry restoration contractor for an opinion!