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crumbling brick foundation

dmauck's picture

Hello all,


I recently purchased a 98 year old house in Denver. The foundation and all exterior load bearing walls are two layers of brick ,with a third layer/veneer of brick on the outside. The brick foundation in the basement has been coated at some point, (i'm not sure if it is original) with a 3/4" layer of concrete/stucco. The stucco coating and mortar joints are crumbling as well as some of the bricks. The main level floor is humped in a couple of places and I assume the walls have cracked at one time or another but I don't believe recently as the "not so new" paint isn't showing any cracks. IU have an engineers report recommending the bad brick and mortar joints be replaced and a new layer of stucco put on. The engineer believes that the deteriorating brick is due to water infiltration (poor drainage in the yard, which I can easily fix). I'm worried that the stucco is actually helping to keep the moisture in the foundation wall. Any help or thoughts on this would be greatly appreciated.


Edited 6/11/2003 12:19:49 AM ET by mauck

(post #57284, reply #1 of 2)

Let me explain what my theories is on this. 


Moisture on the basement walls is the problems.  The water from the outside travels to the inside carrying various salts from the ground and fertilizers.  As the moisture is evaporated on the inside, there is the fuzzy white stuff that remains on the surface to eat up the mortar and bricks.    Stucco is good because it allows moisture to travel thru it and being new will take longer to get eaten up.  If the walls were waterproofed and/or sealed, on the inside, the mortar and bricks will be eaten up just under the seal, resulting in the sealer crumbling off. 


You will see the same thing happening on concrete block walls because the neighbor wets the wall on one side, resulting in a crumbling wall on the sunny side.

(post #57284, reply #2 of 2)

Going beyond theory.........

I've posted about this before. One of my customers has an older home (1913) with brick foundation and brick veneer over frame. In the 1940's the home was converted to a hospital, a CMU addition erected and the front porch enclosed and stucco'd. In the 1970's the house was converted back to a single family residence and because the owner could not or would not spend the money to restore the original brick he just stucco'd over what was already stucco'd and DIRECTLY over all the rest of the brick, too.

During last year's major work (the house was featured on HGTV) we attempted to remove the stucco because the house looked like it had psoriasis. Paint was bubbling and peeling and leaving behind voids where the stucco topcoat disintegrated. In places we could dig out the stucco BY HAND from the mortar joints and it peeled away from the brick in large sheets. Everything we could peel away was very moist. The original mortar was also moist and disintegrating and many of the bricks were loose. In other places, the majority of the house, the scratch and brown were stuck tight and only the topcoat seemed to be affected.

We ended up peeling as much stucco off the brick as possible - couple of whole walls - and then attached Dense Glas Gold, using a direct application of adhesive base coat and sanded color coat to match the rest of the unaffected stucco. The other stucco that was bad was just reparged, primed and painted.

Where we used the Dens Glas a thin opening was created at the top and bottom so air could circulate behind the facade along the deep raked mortar joints. This technique we expect to work. Unfortunately, we expect the other refinished work to eventually fail and where there was no visible problems noted during the original repairs we also expect deteriorization to occur. We were unable to find or cure the underlying moisture wicking problem.

The bottom line - Brick should never be stucco'd because moisture, wicking up from the ground or via leaks, needs to find its way out thru weep holes or evaporate from the face. Brick foundations or piers that are continuously damp but uncovered seem to fare better but still have problems. We have replaced several intermediate piers under this house with steel posts.

Maybe this would not have happened with modern mortar but the 90-year-old stuff just gave up under all that continuous moisture. We still haven't figured out why just portions of the topcoat of a newer 3-part stucco application is turning to sand and not the scratch and brown.