How To Waterproof Brickwork

Water and damp penetrating brickwork is one of the most problematic forms of damp to fix, but don’t despair! We are here with a guide on how to waterproof brickwork.

Brickwork is a strong and reliable material for your home or commercial building; but, it can be hard to keep brickwork in good repair. Brick is extremely porous, making it a sponge for water absorption. Over time and continual exposure to moisture, the brick will start crumbling. Apply an exterior sealant on your bricks before the damage starts in order to protect against both water damage and other damage such as moss growth that can happen over time.

In order to maintain the quality of your brickwork, it’s important that you waterproof your bricks and mortar and seal them against water damage. Here is how to do it…

Tools For The Job

  • Paint scraper
  • Weed trimmer
  • Power washer and/or scrub brush
  • Mildewcide cleaner
  • Plastic or cloth covers
  • Repel 349 brick sealer
  • Pump sprayer and Paint Roller
  • Work gloves
  • Eye protection
  • Protective rubber gloves
  • Mask
  • Warm soapy water

Prepare Surfaces for Cleaning

Firstly you need to use a paint scraper and weed trimmer before applying Repel 349. First, remove old flaking paint with your scraper then pull back any vines, weeds or other vegetation so that you have easy access to all the brickwork and remember to rake and sweep leaves and debris away from the brick’s edge keeping it clean for application.

Apply a mildewcide cleaner to areas with mildew. Remove the mildew using a scrub brush, and use a power washer or hard brush for cleaning previously applied treatments off of brick surfaces and where dirt is present. The brick’s pores must be open to allow for the sealer to properly penetrate.

The key is to start from the top and work your way down so that any dirty water doesn’t drip onto a clean surface below. Let it dry completely before applying the sealant.

Apply Repel 349 Brick Sealer

It’s important to prevent the brickwork sealant from getting on other surfaces so cover plants, bushes, decks, windows and everything else outside that is not supposed to be sealed with a plastic or cloth cover. Cars and other vehicles need to move away from the area as well so they do not get any sealant on them as you spray or apply.

The main thing to keep in mind is that extreme cold or heat can affect dry times or cause blistering. It’s best to apply Repel 349 when the air and surface temperature is between 5°C and 32°C

Put on eye protection, protective rubber gloves, and a mask. Fill up the pump sprayer with Repel 349 before spraying it onto your bricks to ensure that they are protected for years to come. Spread running or dripping paint using a roller or a brush while still wet in order to make sure all brickwork is well covered.

Apply 2nd Coat

Repel 349 is quick to dry, we recommend leaving it for at least 1 hour before applying a second coat


Repel 349 can be applied using a brush or roller if a sprayer is not available

Cleaning brushes, rollers, and sprayer is quick and simple using warm soapy water

Job Done!

What’s your next job?

Do you now need to waterproof your roof or paint an outside sports area such as a tennis court, basketball or netball court? Read more handy “how-to” guides in our blog section. Or contact us to speak with one of our experts for advice on the best protective coating for your next job!

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