Interior wall damage

The foundation of any building is one of its most sensitive aspects. Protecting your foundation means protecting the structural integrity of your home. This is where foundation waterproofing products come into play.

Cracks in your basement floors and walls can pose a serious threat to the foundation. Many buildings have crumbled due to weakened foundations. 

When floodwater leaks through cracks in your basement, it’s not just the strength of your foundation you have to worry about. Water damage can result in mold growth, which is dangerous to your health and your home’s market value.

Cracks in your foundation walls aren’t just all you have to worry about. Openings around your pipe system, basement windows, and gaps around egress can cause leaks. 

Fortunately, there are several waterproofing products specially designed to stop leaks while preserving the safety and strength of your foundation.

Foundation cracks 

Foundation cracks are often non-structural hairline cracks caused when curing concrete shrinks; they are also caused by a poorly settled foundation or wrongly poured walls over time.   

Whether it is poor drainage or poor planning, your home’s foundation is quite vulnerable to water damage. Roof rain gutters may deposit water right into your foundation and weaken it too. Flooding can also be because of poor building materials or terrible maintenance.

If you are inattentive to your house as a homeowner, you will incur losses that could easily have been prevented with quality foundation waterproofing materials and a proper drainage system.

Crack injection: polyurethane or epoxy 

To fix these cracks, you can choose between these heavy-duty waterproofing products: either polyurethane or epoxy. Epoxy and polyurethane injection products are capable of sealing cracks and protecting your basement floors and walls. These products offer an effective long-lasting solution to your wet basement problems.

Before making your choice, there are some questions you need to ask. Is this crack running horizontally? How wide is the crack, less or more than ¼ inch? Does the crack branch off into several veins? 

Polyurethane injection

For cracks wider than ¼ inch, the recommended option is injecting the crack with an expanding waterproofing polyurethane foam. To support this process, you can use carbon fiber straps or/and Kevlar staples to strengthen and support the wall. 

The polyurethane foam injection works well with wider cracks because it fills voids, seals spaces around pipe conduits and prevents the water from penetrating into your foundation effectively. If you are experiencing an active foundation wall leak, polyurethane foam injection is recommended.

The polyurethane foam and injections set very quickly and are incredible waterproofing products. Adapted for small cracks, polyurethane does the job effectively.

Amazon recommended polyurethane: RadonSeal Concrete Foundation Crack Repair Kit (10 ft)

Epoxy injection

For cracks less than ¼ inch, you can use an epoxy, which is non-expanding cement-adhering material, to give your floors and walls structural strength. To increase the strength, you can use carbon fiber straps or/and Kevlar staples.

The epoxy injection works well with cracked concrete floors and walls—bringing the surface together and repairing its structural integrity. Epoxy is great because it gets stronger over time even though it takes a couple of hours to cure.

Ranging from paste-like to thin liquid, epoxy injections are available in many forms and types. By coming in various ranges, epoxy seals the cracks in your basement floors and walls efficiently. 

Amazon recommended epoxy filler: PC-Products PC-11 Epoxy Adhesive Paste, Two-Part Marine Grade, 1lb in Two Cans, Off White 160114

Waterproofing hydraulic cement 

Waterproofing hydraulic cement can be applied to patch holes around your foundation walls and basement floors, keeping your foundation dry. Note that before applying hydraulic cement to any surface, the surface must be dirt-free.

Hydraulic cement might be ineffective for older walls with peeling paint or oxidation and the bond might not be as strong.  

Amazon recommended hydraulic cement: Sakrete of North America 112611 10LB WTR Stop Cement

Urethane caulk 

The Urethane caulk seal is another type of effective waterproofing sealant on the market for crack repairs. While the lifespan of caulk may range from six to twelve months, the caulk’s seal is still effective for temporary protection.

The urethane caulk works best with thin, non-structural cracks and perfect for surface-level, temporary repair. Caulking is perfect for cracks in joints between your foundation and concrete surfaces, like sidewalk or driveway. You can also use caulk for basement floors with shallow hairline cracks.

Note that caulk cannot effectively penetrate a deep crack. Only use caulks when you are certain that the crack does not extend down to the foundation wall’s interior. For deep cracks, about 3 inches deep, I will recommend a concrete injection kit.

The urethane caulk, when applied properly, is relatively durable and capable of keeping water out of your foundation, preventing further eroding or cracking. With a caulk gun, you can apply the urethane caulk easily. But remember to wear disposable gloves while patching these cracks. If you get some caulk on your skin, use a cloth dampened with paint thinner to wipe it off.

Amazon recommended caulk: Sikaflex-221 White 10.1 fl. oz. Cartridge


Repairing the cracks in your basement walls and floors in time is the most cost-effective thing you can do for your building’s foundation. Not acting fast will worsen the matter. Foundation waterproofing products are your best option. But these products don’t offer a one-size-fits-all solution. Depending on the situation of your foundation, there are several foundation waterproofing products you can choose from. The key thing is addressing any issue before it weakens your building any further. 

  1. Hi Bob,

    Very insightful article, it’s good that you’ve included advice on application, e.g. that some of them are not suitable on old walls. When issues such as these arise, you can’t act fast enough!


    • Hi Sharon,

      I appreciate your reading the article. You need to determine which application is the best for the wall you’re repairing. Take care, Bob

  2. Great article, you’ve provided so much information in a condensed form. As a homeowner who isn’t very handy, I found myself learning how important it is to be aware of these foundation issues and what kinds of applications are available to address them. It can seem overwhelming at first, but you broke it down in an understandable way. I live in the Midwest where winters can be pretty brutal, do you know whether there are fixes that are better suitable in colder temperatures? Thanks for sharing this great knowledge!

    • Hi Dereck, Thanks for reading and the comment. The fixes should work fine in the post. Just pay attention to how large the cracks are and the suggestions to which product to use. All the best. Bob

  3. Who don’t have cracks in there foundation. Every home I lived in had a crack and most would leak water. I never thought there was a way to deal with them until I came across your post. It’s very informative and easy to find the product as well. Do we have to dig up the dirt on the outside and apply it there as well?

  4. Very nice article and very informative. There are lots of cracks at my home! I don’t even know how to fix them. It has been there for a very long time. During humid seasons, the cracks are worse. I am afraid there are so insects inside the cracks. So I should buy some Epoxy and polyurethane injection products to fix it. I will take a look at your products mentioned here.

    • Yes, I would fix the cracks in the foundation. If you are worried about whether you can access the damage your self, then I would have a professional take a look at it. They will be able to you an assessment of the damages and what needs to be fixed. All the best, Bob

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