How to Apply Hydraulic Cement to Damp Basements

A basement.
  • 24-48 hours
  • Intermediate
  • 20-50
What You'll Need
Hydraulic cement
Muriatic acid
Pair of gloves
Dust mask

Damp basements can cause structural damage and endanger your health by causing allergies. Water seeps through the walls and results in mold and rust. Water leaks are caused by cracks in the basement floors and walls. You can use hydraulic cement to prevent such issues, as it is a water-resistant product. By following the directions below, you can apply hydraulic cement by yourself without much difficulty.

Step 1 - Take Appropriate Precautions

Hydraulic cement dries very quickly. You should, therefore, only mix a small amount for each application. Hydraulic cement is also caustic, and the dust it produces can cause irritation. You must wear a dust mask and gloves while you are working with it. Work in a well-ventilated area. Since basements are hard to ventilate, use large fans to create a crosswind. If you are using acids to remove debris from the surface, follow all of the necessary precautions.

Step 2 - Prepare the Surface

Prepare your surface for application. Wash the walls or floor to remove the loose mortar, dirt, mold, grease, and other debris. To kill the mold, use a mild detergent with an added capful of bleach in the water. To remove the white powdery substance called efflorescence, use muriatic acid with a wire brush. If the surface has oil-based paint, you must remove the paint as well.

Remember to keep your dust mask on during this step to avoid breathing in bleach or other chemicals. Wear old clothing while handling bleach, because it easily stains.

Step 3 - Prepare the Cracks

Before patching, open cracks with a hammer and chisel. While you are chiseling the crack, remember to undercut the crack in such a way that the crack’s inside opening is wider than the opening of the surface. That is important, as it locks in the hydraulic cement as it hardens. Once you have opened the crack, clean it well with a brush to remove any possible pieces of concrete or dust.

Step 4 - Prepare the Hydraulic Cement

Mix a small amount of hydraulic cement with water in a bucket. You must carefully follow the instructions on the packaging for the proper mixture and consistency. Use a trowel to combine and mix the cement and water in the bucket.

Step 5 - Apply of the Hydraulic Cement

Before the application, use a spray bottle of water to dampen the crack as cement will adhere better to the wet surface. Apply a layer of hydraulic cement to the crack in such as way that the cement is ½ an inch below the base of the crack surface.

Use a trowel to apply another layer of the cement to the crack. Smooth the layer and let it dry for 24 hours before painting the surface. Later, paint the surface with the desired hue.