Almost every building’s structure is made out of reinforced concrete. Concrete is not waterproof and already comes with miniature cracks. Concrete is also porous, which means it is pretty decent at absorbing water and other liquids. While concrete can keep out most of the water, moisture and vapor can still penetrate through the concrete, which can create a whole host of problems such as condensation, water damage, mold, mildew, and wood rot.
The easiest way to start waterproofing is through exterior foundation waterproofing. This is really only applicable if you’re willing to do some serious excavating work outside, as it starts with waterproofing the foundation itself. For DIY and small-scale waterproofing, interior is usually the way to go. If a house was built properly, the exterior concrete foundation should have already been waterproofed to some degree. Excavating requires a permit and a considerable amount of work, but is sometimes necessary if you see moisture or flooding from the base of the floorboards or basement floor.
Exterior waterproofing starts with the installation of a sump pit and drain tile. If you do not already have a sump pit and a sump pump installed, excavation and installation of drain tile and all the necessary equipment will be required. Any considerable cracks on the exterior concrete of the house should be patched with a mortar-based product. Then an exterior masonry sealant should be installed via a roll, spray, or brush.