Basements are the parts of our homes most vulnerable to damage from the elements. This damage frequently manifests itself in such problems as flooding, the excessive build-up of mold and/or mildew, and the passage of potentially harmful gases through the basement walls into your home. As the walls are typically just made of concrete rather than being insulated properly, your home is open to these sorts of problems.
The best way to deal with these problems, of course, is to prevent them. Virtually all basements are constructed from concrete. Concrete, while incredibly strong, is also an extremely porous material. Beginning on its surface, concrete is filled with tiny pores and hairline cracks that extend throughout the material. While concrete is strong enough without any further treatment, it is not as strong and protective as it can be.
Enter concrete sealers. Concrete sealers are products designed and manufactured to help protect the concrete surfaces of your homes. For a basement, the best option would be a penetrating concrete sealer. Sealers of this variety are applied to the surface of the concrete. Once applied, their small particles of protective sealant seep into the concrete through the tiny surface pores, continuing their passage via the pathways of pores and hairline cracks that are natural to concrete. However, once the sealant passes through these miniscule openings, the chemicals react with chemicals present within the concrete, permanently filling up the holes and cracks.
This process not only protects your concrete from the passage of water or harmful gases into your home, but it also fundamentally strengthens the concrete. The concrete becomes denser, filled with more particles of calcium silicate hydrate (or CSH), a naturally occurring part of concrete with which the concrete sealer reacts chemically to increase. The best way to prevent damage to your concrete basement is to treat it early on with a quality penetrating concrete sealer.
Our Take: We like this penetrating concrete waterproofer found at HomeDepot.com.