Cracks in concrete walls can be repaired with a liquid or paste elastomeric compound. The compound is injected into the crack with a bottle or forced into the crack with a spatula. Vertical concrete surfaces include retaining walls, basement walls, and foundation walls. As stated above, contact a professional to obtain a structural component of your home and for retaining walls greater than 4 feet in height.
The following procedure should be followed for cracks in vertical surfaces or cracks that penetrate the entire thickness of the concrete. Some sealant manufacturers, such as Sika, offer sealing or wrap-and-seal systems that actually provide additional strength to existing concrete structures, such as concrete columns. When the entire crack has been sealed except for a single pressure relief point, that final leak is sealed with a molded cement plug. While there are some structural exposures used in some particular damage repairs, in my experience they do not apply to a residential block foundation wall with horizontal cracks, bulges, or buckling.
Once a crack is large enough to insert a dime, you may have a foundation problem and you will need to invest in structural repairs. Usually, within a couple of years, the concrete wall will fluctuate with changes in temperature and humidity and cause the plug to leak again. I recommend the two-part epoxy adhesive for concrete PC* for cracks that do not extend through the entire thickness of the concrete. Airlift concrete experts have professional solutions to fix cracks in your vertical foundations once and for all.
A special example is the use of segmental bridge adhesives that bond post-tensioning precast concrete bridge segments to other structural members or to each other. Polyurea joint filler products for concrete control joints have received attention for concrete control joint filling and are increasingly used in that application, as this material is moisture resistant, has high adhesion properties when used with concrete, and cures in very cold climates. So, see where your crack lies in the range of foundation crack repair scenarios and find out what you can do. You can choose between crack repair kits that use an injectable polyurethane foam or an epoxy, depending on the type of cracks you have.
Your home's foundations, the concrete walls surrounding a basement or low-rise space, support the full weight of the house, so it's natural to worry if you discover cracks in the concrete.