How to Waterproof Concrete Block, Brick and Masonry Surfaces

PROCEDURES: Mix and substrate temperatures should be maintained between 5 °C (40 °F) and 30 °C (86 °F) for at least 24 hours prior to and 48 hours after. 

STEP 1: Surface Preparation: Surfaces to be coated must be structurally sound and clean. Remove all delaminated or unsound concrete by chipping with a hammer and chisel or using a stiff wire brush. Repair all cracks and holes with SAKRETE plug-tite. Remove any dirt, sand, dust, paint, etc. by sweeping, vacuuming, scraping or wire brushing as required. For walls previously painted with anything other than a cement-based paint use a scraper or wire brush and remove as much material as possible to create a good bond. The more paint removed the better the bond. Remove all efflorescence, mold, grease or oil by scrubbing vigorously with a strong detergent solution and flood with large volumes of potable water. Clean the area to be repaired with potable water, leaving the concrete saturated but free of standing water. Sorne very porous concretes may require several applications of water to ensure complete saturation.

STEP 2: Mixing: Mix approximately 293 mL (10 oz) of potable water per 1 KG (2.2lb) of product. ln a disposable plastic pail, put 1/2 of the required water into pail first, add the product and then add balance of the required water. Mix to a pancake batter consistency and then allow the mix to sit for 5 to 10 minutes before applying; avoid a "soupy" mix. A proper mixture should adhere to the brush without dripping. NOTE: For painted surfaces, replace at least 1/3 of the required mixing water with SAKRETE Concrete Adhesive. This will further help the SAKRETE brush'n seal mix to adhere to the original surface

STEP 3: Placing: Dampen walls one hour before application of SAKRETE brush'n seal and allow the moisture to soak in. lmmediately prior to application, the surface should be damp, but not dripping. Maintain this damp surface during the entire application. When ready to begin application, a small amount of water may be added if required to bring the mixture to a batter like consistency. Stir mix occasionally during application. After mixing, apply SAKRETE brush'n seal with a semi-stiff nylon bristle brush. Scrub the mix well into the existing surface, ensuring you fill all the pores, and then finish with a final stroke in one direction. For a decorative appearance, mixture can be finished with a sponge or float. If wall becomes dry or mix starts to pull during application, dampen the original surface again. Do not add more water to the mixture. For normal waterproofing, a two-coat application is recommended. Allow the first coat to cure for 24 hours then dampen surface and apply second coat.

STEP 4: Curing: Allow application to harden sufficiently (approximately 3 hours) then fog spray with clean water. Keep the surface continuously damp for 3 days. This step is critical during hot or windy days.

1. Use only on clean and properly prepared surfaces.
2. Repair cracks.
3. Use a wire brush and/or scrape clean.
4. Remove paint.
5. Apply to a damp surface.
6. Use proper safety equipment (i.e. safety glasses, gloves, etc.).