Chicago, IL · Member since 2017 · 175 posts · 86 votes
Anyone own a 1920s Chicago brick building with stucco over a brick wall?
I patched the stucco with brixement (lime and Portland) a couple years ago. This year water and Ice got behind my patches and they all fell off! The original stucco seems to hold up pretty well. It looks like it might have paint on top that keeps the water out?
Maybe the water is getting in from behind the front bricks and in front of the inside bricks.
If the walls are a sideways brick thick, they may be a double brick wall back to back with tie bricks holding them together (old fashioned way of building) vs modern veneer.
Sometimes during construction the first floor is made with even wider walls to accommodate future upper stories.
The layers of bricks will not have mortar between them (most likely, but who knows).
So if you have water intrusion up higher, it may come down there and leak out behind the stucco and when it freezes bingo stucco pops off.
The intrusion could follow an old window casing down and leak in a hidden spot under the sill and flow down, or on an angle.
If you are using a good stucco contractor and he is baffled, this might be it....or it might not be it....
Maybe affixing metal lath to the area might help--but if it is a water issue,,,that water will have to go somewhere, and if its bundled between the bricks when it freezes...the bricks might pop.
Maybe shield the areas really well with plastic duck taped up there, and if the brick is wet or the taped cover holds water when you open it after a storm...you may have figured it out. Then all you have to do is find the point of intrusion, which could be hidden under a window sill (calking might help).
I don't know that this is you problem but I do know how some older brick buildings were built and it seems like a possibility.
Newer brick facads have weep holes at the bottom to exhaust water.
Maybe the water is getting in from behind the front bricks and in front of the inside bricks.
If the walls are a sideways brick thick, they may be a double brick wall back to back with tie bricks holding them together (old fashioned way of building) vs modern veneer.
Sometimes during construction the first floor is made with even wider walls to accommodate future upper stories.
The layers of bricks will not have mortar between them (most likely, but who knows).
So if you have water intrusion up higher, it may come down there and leak out behind the stucco and when it freezes bingo stucco pops off.
The intrusion could follow an old window casing down and leak in a hidden spot under the sill and flow down, or on an angle.
If you are using a good stucco contractor and he is baffled, this might be it....or it might not be it....
Maybe affixing metal lath to the area might help--but if it is a water issue,,,that water will have to go somewhere, and if its bundled between the bricks when it freezes...the bricks might pop.
Maybe shield the areas really well with plastic duck taped up there, and if the brick is wet or the taped cover holds water when you open it after a storm...you may have figured it out. Then all you have to do is find the point of intrusion, which could be hidden under a window sill (calking might help).
I don't know that this is you problem but I do know how some older brick buildings were built and it seems like a possibility.
Newer brick facads have weep holes at the bottom to exhaust water.
Hey @Connor O'Brien - This is a tricky issue that isn't ideal. In Chicago because of the freeze and thaw it makes it nearly impossible for the stucco to have a long shelf life.
I am not a masonry expert, but in my opinion, the optimal fix would be to remove all the stucco and tuckpoint all the brick.
@Connor O'Brien water infiltration is your issue. Any gaps or cracks above your patches are letting water in that pops the plaster.
There are a lot of other potential things going on here. Is the brick structural, or just a veneer. If it is structural, the walls will likely be several layers of brick all the way through to the inside as well. If they are veneer, then there is likely just a single layer of brick that is hanging on the face of the building.
@Connor O'Brien that is not stucco that is cement. You need to make sure they get all of the loose concrete off and then skim coat. Not ideal but not end of word. I have a great vendor that can help if you want to DM me.