How to Waterproof a Basement with Mortar

  • 10-16 hours
  • Beginner
  • 600-1,000
What You'll Need
Epoxy or latex for a waterproof mixture
Garden hose with a spray nozzle

Having a waterproof basement is becoming a popular option for homeowners because it creates extra space to make into a guest bedroom, a workplace, or an entertainment room.

Hiring a professional to waterproof the basement is costly. If a homeowner is savvy with home improvements, waterproofing the basement is an easy project if you follow these steps.

Covering up Cracks

Small cracks in the basement area (about 1/8-inch or smaller) should be repaired using a waterproofing mix. Larger cracks should be cleaned and patched. Work gloves are recommended, as some harsh chemicals are used in the mixture.

Preparing The Mortar Mix

Mix the mortar with a consistency of one part cement to two parts fine sand. Mix the materials with the right amount of water to achieve the correct consistency. Apply the mixture with a putty knife, apply the mortar into the cracks where water is seeping through the wall.

Source Waterproof Mortar on Amazon

Chipping Process

Chip the broken areas with bigger holes. After chipping, fill the void with the mortar mix, and smooth the area with the trowel.

Filling the Cracks

A weep pipe should be inserted into the wall if the water is trapped against the exterior wall. The cracked part where the weep pipe was installed should be filled with the mortar mix. Allow the mortar mix to fully dry.

Readying for Waterproofing

Remove the pipe, cover the hole, and make a cement plug by shaping the mixture into a cone that is bigger than the hole. The smaller end of the cone should fit the hole and hold it in place. The plug should be held for several minutes to allow it to set. The basement is now ready for waterproofing.

Basement Wall Preparation

Use a garden hose set onto fine spray to wet the basement walls. Dampen the walls, creating no standing water on the surface prior to adding the waterproofing mix.

Applying the Mixture

The walls and floor should be treated with epoxy or latex waterproof mixes. A mixture of plain cement and water made into a creamy consistency is another option. Rub this mixture in circular motions onto the wall to fill the pores. Apply the mixture from the bottom part then leading to the top. Additional coats may be applied.

Wetting the Area

Dampen the wall or floor area again after the coating has dried. Wet it completely and let it stand for several hours. The lower area should be wetted using a garden hose once the wall parts have dried. Apply the second coat of the mixture onto the basement surfaces.

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