How To Waterproof Concrete Against Hydrostatic Pressure

Clean the concrete of dirt and grease using a pressure washer or a wire brush and water. If you're using a wire brush, force loose concrete and other matter from cracks and holes using a hose.

Fill cracks and holes with a concrete patch compound and allow the patched areas to dry completely. This drying time will vary depending on the product. Follow the manufacturer’s directions on the label for ideal drying time.

Apply water to the concrete prior to waterproofing so that it is damp, but not wet.

Mix a crystalline integral waterproofer in a bucket according to the label directions. The mixture typically will contain about two parts water to one part powder and should create a slurry that has a creamy consistency. Mix only as much waterproofer as you can apply in 20 minutes.

Apply the mixture to the concrete in an even layer using a concrete brush. Stir the mixture frequently as you apply it. The mixture might appear to set, but don’t add more water. Instead, stir the mixture to restore its creamy consistency.

Allow the first coat of waterproofer to dry for the time specified by the label, and then apply a second coat.

Keep the concrete damp and protect it from direct sunlight, wind and frost by covering it with a tarp for at least five days following application.