Damp-proofing is usually done in situations where direct water penetration is not the source of moisture in a basement. Damp-proofing is typically cheaper to apply, but its effectiveness is limited because the tar-based applications will only “retard” moisture penetration, not prevent it. In addition, damp-proofing products can become brittle once they cure. As the home or building foundation settles and hairline cracks appear, the tar-based coating will not stretch to bridge the cracks and this allows moisture to penetrate into the basement. Many homeowners who have problems with a wet basement and dig up the exterior foundation find that these tar based products have started to flake off the wall within a few years of being applied. DrainCom recommends that waterproofing be considered over damp-proofing as it is much more effective in the long term.