Dampproofing

To prevent water problems with foundations: ensure that the footing and sub-slab area is properly drained.

• use granular fill to backfill the wall.

• grade the earth around the house away from the building.

• use eavestroughing and downspouts to take rainwater away from the foundation.

• dampproof the wall on the exterior from grade level to the bottom and over the joint with the footing. Do not connect roof drains to perimeter drains.

The material most commonly used for dampproofing is a spray-on or mop-applied bituminous substance. It fills the pores in the concrete, reducing the penetration of liquid water due to pressure against the wall and capillary action. This material has been used by builders for many years. Other than it is easy of application it has very few positive aspects. This petroleum based product leaches chemicals into ground water, and although it looks good once applied, does very little if anything to keep moisture out of the basement.

Specially designed foundation membranes that provide both moisture protection and free-flow drainage capabilities are also available. These materials may be semi-rigid plastic sheet materials with dimples or semi-rigid fiberglass batts. One such material would be ms delta’s “delta wrap”. It provides a break between the soil and foundation wall to allow free flow of water to the weeping tile system at footing level.

Newer “peel-and-stick” applications are also available. This material has a peal away back that then sticks to the foundation surface and a water resistant side opposite, that protects the wall from direct water penetrations.