Repair of Active Expansion Cracks in a Masonary House
I am working on a 1950’s ranch style house that is solid masonry construction.. It is block construction with a face brick veneer. The house is built on a hillside, so the side foundation walls are stepped to allow it (the foundation) to follow the contour of the hillside. What I am needing an expert opinion on is how to reseal the various material joints (brick,stone,block,concrete) to prevent water leakage and intrusion. There is a horizontal stone beltline about 3′ from the top of the foundation that separates the various brick colors, it also is used for the window sills as well. The joint here has a horizontal hairline crack completely around the house at this joint as well as at the vertical connections between the stone segments. I assume it is because the stone and brick expand and contract at different rates from one another. Also, and more importantly, where the blocks and bricks sit on the top of the foundation, there is also a whole house (or close to it) crack. This allows water to seep into the basement area by some of the stepped areas of the foundation. The mortar used is not the typical lime mortar, instead it has an extra portland cement percentage to it allegedly to make it stronger. Made stronger it was indeed, as there are a few settling cracks in the side wall that extend from top to bottom both following the mortar joints and also cracking the bricks and blocks themselves.
It was suggested that I have the joints tuckpointed, but I cannot see how an approximately 1″ deep layer of new mortar will hold, when the full wall 10+” thick has cracked and let loose (this is at the foundation joint, I cannot see behind the beltline as there are interior finishes covering the inside of the wall). My thoughts are leaning to possibly grinding the joint maybe 1/4″ or so and then filling with Sikaflex or equivalent. Any help on this would be greatly appreciated.
Replies
Any history on when the cracks began to occur?
From the pictures (not knowing what the interior wall/ceiling materials look like) you posted I'd be very concerned about structural issues with the foundation / settling on the site slope causing further problems.
You know any engineers who might have an opinion on whether this place is stable now?
RE: History of Cracks
The cracks have occured over the life of the building.... one here, one there. I am now involved and am wanting to prevent further damage. I see that there are some drainage issues that will need to be addressed soon on the upslope side of the house, but other than that I would just like to seal things up to prevent further damage. There are a few small cracks in the plaster, but for the most part, doors and windows work fine with no evidence of binding etc. There is a whole laundry list of things that will eventually need to be done, but I have to start somewhere...
As far as stability goes, Obviously there must be some movement or stresses to have caused the cracks in the first place. In some informal discussions with engineers, I was told that a hillside house will always experience stresses that the average house will not. As long as my primary foundation is good, I should not have any worries or so they said.
Photo 2 cracks are in a sidewall? If you could, post a profile of the house showing how it sits on the slope. Need to know which side these cracks appear to evaluate. Photo 2 might show a foundation problem, not unusual. Unlikely that's caused by "expand and contract at different rates from one another". If the foundation is moving, cracks will happen. You are correct about the tuckpointing.
RE: Additional Photos
Thanks for the reply, It is dark out here in chilly chicagoland so the pictures will be forthcoming tomorrow (should be by noon)
Upslope drainage problems
Deal with those upslope drainage problems. You might be able to get away with some surface contouring. Divide your upslope yard in half (if you have such a yard), along a line going through the center of your house pointing directly upslope. (Adjust the line sideways if one side of the yard is higher than the other, "sides" being either side of the line.) A couple of gentle swales or valleys, about 10-15' out from your foundation, can direct surface runoff around the house. The result is like a "saddle" whose centerline is aimed upslope. Tearing up the lawn is a pain, but less so than French drains, which silt up in time anyway. You may be already on top of this approach, but it's an often-overlooked solution.
Additional Photos
OK, here are some additional photos showing the side slopes and somoe more cracks as well as the top of the foundation wall popping. So far I do NOT see any cracks in the foundation wall proper. They are just between the bricks and the concrete.
Thanks again guys.