I’d like to share a case study of a recent inspection I completed. Recently I was asked by a homeowner to evaluate their rear basement foundation wall and, in addition, to review the five different foundation repair proposals they had obtained from different foundation repair contractors. Their house is a common two-story Colonial with an unreinforced 8-inch thick Concrete Masonry Unit (CMU) wall. When I say unreinforced, I mean that it did not have any steel reinforcing bars (rebar) in the wall like what’s required in new construction today and since the 2000’s. The rear yard sloped towards the rear foundation wall. Because the basement was finished, the wall bowed approximately two inches before they removed the drywall to find the cracked and bowed foundation wall.
The homeowner had diligently obtained the five proposals from foundation repair contractors, but each one had a different scope of work. Understandably, they were confused as to which way was the correct way to repair their basement foundation wall. First, I’m going to put it out there, I do not work for any foundation repair contractors so I can provide an unbiased opinion. The proposals included wall anchors and carbon fiber strips for reinforcing the wall, and some contained interior and exterior waterproofing for the foundation wall. But none of them did anything to address the root cause of the problem, the rear yard sloping towards the house!
So what did I recommend? First, the slope of the rear yard needed to be addressed with creating a swale along the rear yard to channel water away from the foundation. A swale is a wide, shallow ditch so that once grass grows in the swale, it blends into the grass yard. I usually recommend making it wide and shallow so that you can mow it easily after the grass has grown into the swale. Then, I recommended some type of waterproofing. Exterior is typically preferred since it keeps the water outside of the foundation, but is also more costly. Interior waterproofing works as well, is less expensive, but you typically have a sump pit and pump in the basement to maintain. Finally, the bowed foundation wall needed to be reinforced. Wall anchors are less expensive than carbon fiber strips, but do have to be torqued every few months. The majority of homeowners either forget to torque the wall anchors, don’t know they are supposed to torque them, or simply do not know how to torque them. So if you’re finishing the basement or just don’t want to deal with the maintenance of the wall anchors, carbon fiber strips would be needed. Just in case you were wondering, I did not specifically recommend any of the proposals. I simply gave them my general recommendations for the repairs, and then let the homeowners make the decision of which proposal to go with to repair their foundation wall.
The reason I wanted to share this story with you was to let you know that sometimes aren’t needed to inspect a wall, floor or other structural element of a house. Sometimes we are called in to provide an unbiased opinion when homeowners are presented with multiple repair options from contractors.
So if one of your client’s has a similar situation with their foundation wall or any other structural concern with their house or building, please give me a call at 412-770-7590 or email BobTheStructuralEngineer@gmail.com.