Although they can be a sign of foundation settlement, vertical cracks in a foundation wall are not necessarily a sign of serious structural damage in your home. Vertical cracks are often caused by the shrinking of concrete as it cures; if the edges of a small crack feel even as you run your fingers along the sides, this is likely the reason why. However, it's always a good idea to have a professional look at the problem, so you can be sure that the problem is not major before it gets much worse.
It's possible to permanently repair a foundation wall crack. Minor cracks that show no leaking may need only a cosmetic repair, and will not be a problem unless they reoccur. And when it comes to a leaking crack where there is no threat of foundation failure, there have been many innovations in wall crack repair that have made it possible to repair the cracks without high-pressure injection equipment or the need to drill holes in the foundation wall.
Caulk Crack Repair
Many homeowners will try to patch a leaking crack with a caulk seal. However, this fix is only skin deep, and water is still filling the crack behind the patch. Efflorescence- a white, powdery mineral salt that is deposited by the water, will break the seal of caulk, while the pressure from the water will cause it to peel off. This repair lasts about 6 months to a year.
Hydraulic Cement Crack Fillings
Instead of using caulk, many homeowners- and even some contractors- will attempt to repair the crack by chiseling it into an inverted V-groove and fill it with hydraulic cement. This rigid cement will plug the hole, but it bonds with the cement very poorly. As the concrete wall fluctuates with different temperatures and moisture levels, the plug will weaken. Efflorescence will begin to work its way around the rigid cement fill, and soon after water will begin to leak through. This fix usually lasts about two years before it fails and allows water into the basement or crawl space again.
Epoxy Crack Injections
Sometimes, contactors will inject epoxy or even grout into a foundation wall crack to seal it. These seals are powerful and can even make the basement wall stronger. However, epoxy can only be applied to a completely dry surface, and because it cures very slowly, it can run out the other side of the wall crack before it hardens, making it ineffective.
Like hydraulic cements, epoxy crack fillings are rigid, inflexible plugs. As the concrete wall fluctuates, this plug will also fail as the seal bonds. In some situations, it can even lead to a new crack developing near the existing crack, as the water pressure may have caused the crack in the first place was never addressed.
Fixing Wall Cracks from the Exterior
One extreme repair method is to excavate the entire outside of the wall where the crack appeared. Landscaping, sidewalks, steps, gardens, porches, and anything else outside of the foundation will need to be removed while mounds of dirt are piled on the lawn during excavation. Once this has been accomplished, multiple layers of synthetic waterproof material are installed to prevent any further movement of the wall and lock water out.
After this has been completed, the mounds of dirt and landscaping are returned, and the repair is complete. However, the excavated soil will begin to settle, and you will need to regrade it a year later so water does not pool around the foundation.
One of the better methods of sealing leaking wall cracks is to inject it with a urethane injection. This method effectively seals off the crack without running out the other side. Unlike the rigid alternatives, it is able to flex slightly with wall movement, allowing it to last longer than all the alternatives previously mentioned. However, a 1/16th inch crack can easily expand to 1/8th inch, and urethane isn't able to expand nearly that much. Eventually, even this solution will fail, and the gap will begin to leak once more.
Polyurethane Polymer Injection
The best (and least invasive) method to repair a leaking wall crack is to inject a high-viscosity polyurethane polymer into the crack. Unlike epoxy, polyurethane can bond well to both wet and dry concrete, and its high viscosity will allow it to fill even hairline cracks.
Unlike urethane, a polyurethane polymer can be designed to expand as much as 20 times its volume if needed. This means that the seal it provides will not be lost as the wall continues its natural process of shifting and moving. And unlike expensive exterior methods, the work can be completed in a few hours, with no need to dig up the yard.
The Polyurethane Polymer Wall Crack System
Even polyurethane polymer injection can experience partial failure. Although 95% of the water should still be stopped, you hired your contractor to stop ALL the water. Many contractors will take their installations a step farther with the patented polyurethane polymer wall crack system.
Polyurethane Polymer injection is the first line of defense with this type of wall crack system. However, if water makes its way past this, a foam strip is installed over the top of the crack repair. This strip runs beneath the floor, guiding any extra water into a small drywell dug there.
To finish the installation, the crack is covered over with a special coating to give it a tooled-off look, and the drywell is covered over once more with concrete. The end result is a professional-looking and reliable wall crack repair that comes with a written warranty. The installation is fast, easy, and works almost all the time.
Foundation wall cracks can also be a sign of foundation settlement, with part of the house sinking unevenly and causes the foundation to crack. This is a very serious problem, if you think that a problem like this is possible, it's best to consult a professional right away. To learn more about foundation settlement repair options, click here.