How to Seal a Brick Wall

To prevent moisture, which can lead to mold and mildew growth, you'll have to seal the brick wall.

1. Spread drop cloths over the floor or ground against the brick wall to protect your floor's finish or lawn and plants.

2. Mix 4 parts of warm water with 1 part of TSP in a bucket. Put on rubber gloves and stir the TSP and water with a stiff-bristled brush. Let the brush soak in the mixture for about 10 minutes to saturate the bristles.

3. Thoroughly scrub the brick wall with the solution, getting all dirt and grime off the surface. The bricks in the wall should be free of any soil or grime.

4. Dry the brick wall with a heat gun or hair dryer once completely clean. Do not let the brick wall air dry or water spots may appear. Use the heat gun or dryer to penetrate the pores in the brick wall. Rinse the bucket out and set aside once the brick wall is dry.

5. Open a can of concrete and masonry sealer with a flathead screwdriver. Dip a paintbrush into the sealer and apply the first coat. Brush from top to bottom slowly, treating each brick with the sealer. Let dry as long as recommended by the manufacturer thereafter.

6. Brush on a second coat of concrete and masonry sealer after the first coat has dried. Let dry for 24 to 48 hours or as long as directed by the manufacturer.