Parging a concrete foundation wall is an easy way to cover and strengthen an otherwise susceptible surface. This thin coating of material is particularly useful for older concrete block foundations which are held together with mortar. The process can be completed in a single day of work. Enhance the exterior of your foundation with a basic parge application and reap the benefits of a protected foundation.
Scrape off loose bits of mortar from the foundation wall with a drywall knife.
Scrub down the wall to remove additional loose bits and debris from the foundation with a stiff bristled wire brush.
Spray a fine mist of water onto the foundation so that it is damp to the touch.
Mix together one part Portland cement, 1/2 part hydrated lime and three parts washed sand in a wheelbarrow.
Slowly add water to the dry materials in the wheelbarrow and stir together with a shovel. Stop once the material has the consistency of peanut butter.
Scoop the mixture onto a flat trowel and spread it onto the base of the wall with upward strokes. Continue parging the foundation until it is covered with an even coat. Aim for a thickness of 1/4 inch.
Run a damp broom over the recently applied coating. Allow it to dry for 24 hours.
Dampen the foundation with a mist of water, then apply a second coating using the same process as the previous day. The second coating will dry in 24 hours.