When moisture infiltrates the interior walls of your home, it can cause mold, mildew, cracking or even structural damage like wall displacement. Moisture most commonly impacts the interior walls of basements as groundwater and rainwater can seep through small openings in concrete basement foundations. In addition, hydrostatic pressure, or the pressure of standing liquids, can build up around the perimeters of interior basement walls, which is what causes cracking and structural damage. Fortunately, there are several strategies you can use to waterproof interior walls.
Sealers are specialized chemicals that you can apply to wood or masonry interior walls just as you would apply a coat of paint. However, unlike paint, a sealer fills in the minute gaps and pores in a material, making the material watertight and less likely to become inundated with water. As LookSmart Home Inspection notes, while sealers are ineffective at relieving hydrostatic pressure behind interior basement walls, sealers can limit spalling, which is the deterioration of concrete foundations due to excessive humidity and moisture.
Water Resistant Drywall
Due to the absorption ability of drywall, coating it with a sealer is not the best waterproofing option. Also known as plasterboard, drywall consists of a gypsum core surrounded by thick paper wrappings. When these wrappings become wet, they can transmit moisture to the gypsum, comprising the integrity of an entire drywall panel. If you are adamant about using drywall for interior walls in a moisture-prone area, such as the basement, Ask The Builder recommends using green board. Green board is a specialized type of drywall that features green, moisture-resistant wrappings. In addition, the board's gypsum core often has a wax or silicone coating, which protects the core from moisture.
Installing a sump pump is an interior wall waterproofing idea that is specifically suited to basements. A sump pump utilizes a centralized sump, or pit, which "pulls" water away from interior walls and collects it using the natural force gravity. A pump then discharges the water from your home, sending it outside.
A French drain is a plumbing system that you can use in conjunction with a sump pump. Installing the drain requires jack-hammering out a 4- to 6-inch wide gap or channel along the interior perimeter of your basement walls. A perforated pipe, which is sloped slightly toward the sump, rests in the gap. In comparison to using a sump pump alone, a French drain helps guide water away from interior walls more readily, increasing the pump's effectiveness at waterproofing walls.