How to Seal Brickwork: What You Need to Know

Brickwork is a popular and durable choice for exterior walls, driveways, landscaping features, and outbuildings. However, while bricks are strong and long-lasting, they are naturally porous and are not waterproof. This means that, in certain situations, sealing your brickwork can provide important protection. Whether you're looking to safeguard a patio, driveway, or exposed brick wall, it's essential to understand when and why you might want to seal your brick surfaces.

In this blog post, we’ll cover everything you need to know about sealing brickwork, from understanding the importance of waterproofing exterior brick to offering practical brickwork tips for your DIY home improvement projects.

Why Should You Seal Brickwork?

Although brick is known for its strength, it’s important to remember that it’s not entirely impervious to the elements. Over time, moisture can seep into bricks, causing them to weaken, crumble, or become vulnerable to damage. In some cases, sealing brickwork can significantly extend the lifespan of your exterior walls, patios, driveways, and other brick features.

Sealing exterior brick provides an extra layer of protection by repelling moisture, preventing damage from freeze-thaw cycles, and helping to maintain the overall integrity and appearance of the brickwork. Waterproofing exterior brick is particularly important for brick surfaces exposed to the elements, such as garden walls, driveways, and outdoor structures.

What Happens If You Don't Seal Brick?

If you live in a dry climate or your brickwork uses modern masonry with a cavity for water drainage, you may not need to seal your bricks. However, for most homeowners, neglecting to seal brickwork can result in various long-term issues.

Here are some risks associated with unsealed brickwork:

• Moisture Damage: Without proper sealing, moisture can enter the brick surface, leading to freeze-thaw damage in colder climates. This can cause the bricks to crack, crumble, and deteriorate.
• Colour Fading: Sunlight and rain can degrade the colour of your bricks over time. Sealing the bricks helps to protect them from fading and also prevents efflorescence, a white powdery deposit that appears due to mineral deposits in the brick.
• Foliage Growth: Moisture trapped in unsealed bricks can encourage the growth of moss, weeds, and grass, particularly on block paving surfaces. This can cause further damage to the bricks over time.
• Crumbling and Spalling: When moisture enters the brick, it can cause the outer layer to peel away, leading to cracks, spalling (flaking), and further structural issues.
• Mould and Mildew: Unsealed brickwork is a breeding ground for mould and mildew, especially in areas with high humidity. Sealing the brick helps to prevent the growth of these harmful substances.

Sealing your brickwork is a simple and effective way to preserve the aesthetic appeal and structural integrity of your outdoor spaces.

Do You Need to Seal Interior Brick?

Interior brick surfaces can benefit from sealing, particularly if the area is prone to moisture. Kitchens, bathrooms, and basements with exposed brick walls are more susceptible to damp, so it’s a good idea to apply a water-resistant sealant. This will help prevent moisture damage, mould, and dust accumulation.

If you have exposed brick in a decorative area, sealing can also make the surface easier to clean and maintain. Watered-down PVA building adhesive is a common option for sealing interior bricks, as it creates a protective barrier and can also act as a base for painting if you wish to update the look later on.

How to Seal Brickwork: Step-by-Step Guide

Sealing your brickwork is a straightforward DIY home improvement project. Follow these steps to ensure your brick surfaces are well protected:

Step 1: Clean the Brick Surface

Before applying any sealant, thoroughly clean the brick surface to remove any dirt, dust, or plant material. Use a broom and a wire brush to scrub the bricks, paying extra attention to corners and joints. This step ensures that the sealant adheres properly to the surface.

Step 2: Wash the Bricks

Next, wash the bricks with a mild detergent mixed with water. Use a sponge or cloth to scrub the surface and remove any remaining grime. Be sure to dry the bricks completely with absorbent cloths or towels. It’s best to leave the bricks to dry overnight before moving to the next step.

Step 3: Repair Any Damage

If your brickwork has any cracks or crumbling sections, now is the time to make repairs. Use a brick repair mortar to fill in damaged areas and allow the repairs to dry. Once the brickwork is fully dry and the repairs are complete, ensure the surface is free of dust and debris before moving on.

Step 4: Apply the Sealant

Choose a masonry sealant that best suits your needs. For exterior brick, opt for a hydrophobic (water-repelling) option to ensure maximum waterproofing. There are different application methods, including using a paintbrush, roller, or low-pressure spray applicator.

Start at the top of the brick surface and apply the sealant in horizontal strokes. It’s better to apply multiple thin coats than one thick coat. Allow each coat to dry before applying the next. This ensures the sealant fully absorbs into the brick and provides an even, protective layer. After applying the final coat, leave the surface to dry completely.

Step 5: Test for Water Resistance

Once the sealant has dried, you can test the brickwork to ensure it is waterproof. Pour a small amount of water onto the surface. If the water beads up and doesn’t absorb into the brick, the sealing process has been successful.

How Long Does Brick Sealing Last?

Typically, most brick sealers will last for about 5 years, depending on the climate and level of exposure. However, some high-quality sealants may last up to 25 years before requiring reapplication. If you're unsure whether your brickwork still has its protective layer, you can test the surface by applying water and observing if it’s repelled or absorbed.

DIY Home Improvement: Brickwork Tips for Long-Lasting Results

Sealing your brickwork can be a great DIY home improvement project, but it’s important to follow the right steps to get the best results. Here are a few brickwork tips to keep in mind:

• Choose the right sealant: Not all sealants are the same. Some are glossy, some matte, and others offer enhanced waterproofing features. Always select a product that suits your needs, particularly if you're sealing exterior walls that will be exposed to harsh weather.
• Plan your timing: Avoid sealing brickwork during extremely hot or rainy weather. Ideally, seal your bricks on a dry day when the temperature is mild to ensure the best results.
• Repair damage first: Any existing cracks or issues should be repaired before you seal the brick. This will ensure the sealant adheres properly and doesn’t trap moisture beneath the surface.
• Regular maintenance: Over time, even sealed brickwork can lose its effectiveness. Regularly check your brick surfaces for signs of moisture penetration and reapply sealant as needed.

Conclusion

Sealing your brickwork is a smart and simple way to protect your investment, whether you're looking to maintain the appearance of your exterior walls or safeguard your driveway and landscaping features. By following these easy steps and using the right tools and products, you can ensure your brick surfaces stay strong, waterproof, and aesthetically pleasing for years to come.

For more brickwork tips and expert advice, consult our building supply guide and explore additional resources for your DIY home improvement projects.