A client who was buying a home recently negotiated the repair of two vertical cracks in the poured concrete foundation walls. The repair was supposed to be made using a process called epoxy injection.
At the pre-settlement walk through, the cracks were found to have been repaired using patching cement. The client requested advice on the adequacy of the repair.
The cracks, which had been identified during the home inspection on the house, were not an immediate structural concern. They were narrow and at the tops of the walls. Also, they appeared to be a long-standing feature, with no evidence of change in the recent past to suggest continuing movement of the walls.
There was, however, evidence of ground water seepage through one of the cracks, consisting of water stains on the wall below the lower portion of the crack. Epoxy injection was recommended because it would provide a high degree of assurance that seepage would not recur.
Epoxy injection has been widely used for concrete repair in industrial and public works applications, and is coming into widespread use as a technique for repair of residential poured concrete foundations. It is generally superior to patching cement, hydraulic cement or caulk for the repair of cracked concrete. The technique consists of injecting epoxy adhesive at low pressure into injection ports installed in holes drilled at intervals along the crack. Injection is performed at each hole until epoxy has filled the entire depth of the crack and appears in the next injection port.
Because of the strength and the adhesive of epoxy, and because it bonds the broken concrete through the entire depth of the crack, epoxy injection forms a permanent, waterproof repair.
The repair that was made using hydraulic cement may have successfully sealed the cracks, but its reliability is uncertain. Any slight movement in the walls will cause the cement to crack, allowing leakage once again.
Meet the inspector
Dean Uhler has been a home inspector for more than 12 years and is president of Baltimore-based Boswell Building Surveys Inc. Uhler is a member of the American Society of Home Inspectors (ASHI) and is the treasurer of the Greater Baltimore Chapter of ASHI. Questions, with name, address and daytime telephone number, about homes and home inspections can be faxed to 410-783-2517, e-mailed to firstname.lastname@example.org or mailed to Inspector's Eye, Second Floor, 501 N. Calvert St., Baltimore, Md. 21278-0001.