The Role of Masonry Sealants in Protecting Brickwork

What Are Masonry Sealants?

Masonry sealants are specially formulated products designed to protect brick, stone, and other masonry surfaces from water damage, staining, and deterioration. These sealants create a protective barrier on the surface of the brick while allowing it to breathe - meaning moisture can escape but is less likely to penetrate the surface. This breathability is essential, as trapped moisture can lead to damage over time.

Sealants come in various formulations, including penetrating sealants that seep into the pores of the brick and surface sealants that create a protective layer on top. Choosing the right sealant depends on your specific brickwork needs, climate, and aesthetic preferences. Below we'll look at the benefits of using masonry sealants for brickwork

1. Water Protection

How It Helps:

Water is one of the primary causes of damage to brick structures. When bricks absorb moisture, it can lead to issues like mold growth, efflorescence (white powdery stains), and even structural damage as the water expands and contracts with temperature changes. Masonry sealants prevent excessive water absorption, keeping your brickwork dry and reducing the risk of water-related damage.

Best for:

Homes in areas with frequent rain or high humidity, where brickwork is exposed to moisture for extended periods.

2. Prevents Freeze-Thaw Damage

How It Helps:

In colder climates, water trapped in bricks can freeze during winter, expand, and cause cracks or spalling (surface flaking). This freeze-thaw cycle is a major cause of brick deterioration in regions with harsh winters. A quality sealant minimizes water absorption, reducing the risk of freeze-thaw damage and preserving the structure of the brick.

Best for:

Brick structures in colder climates, especially those exposed to snow and freezing temperatures.

3. Reduces Efflorescence

How It Helps:

Efflorescence, the white powdery residue that appears on brick surfaces, occurs when water draws salt to the surface. While not harmful to the brick itself, efflorescence can detract from the brickwork’s appearance. A masonry sealant prevents water from penetrating the brick, helping to reduce efflorescence and keep your brickwork looking clean and vibrant.

Best for:

Decorative brickwork and exposed brick facades where appearance is a priority.

4. Protects Against Stains and Pollution

How It Helps:

Brick structures located near busy streets or urban areas can be exposed to dirt, dust, and pollutants that lead to staining over time. Masonry sealants create a barrier that helps protect against staining, making it easier to clean off surface dirt and maintain the appearance of the brickwork.

Best for:

Brick buildings in urban or high-traffic areas, where pollution and dirt accumulation are common.

5. Extends the Lifespan of Brickwork

How It Helps:

By protecting brick surfaces from water, stains, and environmental damage, masonry sealants help extend the life of the structure. Regular application of a sealant prevents minor issues from escalating into costly repairs, making it a valuable investment for long-term brickwork preservation.

Best for:

Historic or older brick structures, as well as new builds, where the goal is to preserve and protect the original brickwork.

Types of Masonry Sealants

There are two main types of masonry sealants, each with its own set of benefits. Understanding the difference between these types can help you choose the right sealant for your specific needs.

• 1. Penetrating Sealants: Penetrating sealants are designed to seep into the pores of the brick, forming a protective barrier below the surface. They are breathable, allowing moisture to escape from the brick while preventing new moisture from entering.

Ideal For:

Exterior brickwork and surfaces in need of durable, long-term protection from water. Penetrating sealants are also recommended for historic brick buildings where preserving the original look and breathability of the material is essential.

• 2. Surface Sealants (Film-Forming Sealants) Surface sealants create a protective layer on top of the brick, offering enhanced protection against staining and dirt. However, some film-forming sealants may reduce the breathability of brick, which can be a concern in humid environments.

Ideal For:

Decorative indoor brickwork or brick walls where extra protection against stains and pollution is needed. These sealants can also add a subtle gloss to the brick surface, enhancing its appearance.

How to Apply Masonry Sealant to Brickwork

Applying masonry sealant requires careful preparation and attention to detail. For best results, consider consulting a professional mason, but if you plan to DIY, here are some steps to follow:

• 1. Clean the Brickwork: Remove any dirt, mold, or efflorescence from the brick surface. You can use a mild detergent and a soft brush, or a power washer for exterior walls (ensure the pressure is appropriate for brick surfaces).
• 2. Allow the Brick to Dry: Ensure that the brickwork is completely dry before applying the sealant. This is essential for allowing the sealant to penetrate or adhere to the surface effectively.
• 3. Choose the Right Sealant: Select a sealant based on your brickwork’s location and exposure. For exterior walls, choose a high-quality, breathable penetrating sealant. For indoor decorative brick, a surface sealant may be appropriate.
• 4. Apply the Sealant Evenly: Use a brush, roller, or sprayer to apply the sealant evenly across the brick surface. Be sure to cover all areas, focusing on mortar joints as well as the bricks themselves. Apply multiple coats if needed, according to the manufacturer’s instructions.
• 5. Allow the Sealant to Cure: Once applied, allow the sealant to cure for the recommended time. Avoid exposing the brickwork to moisture until the sealant has fully set.

When to Reseal Brickwork

Masonry sealants don’t last forever, and regular reapplication may be necessary to keep your brickwork protected. The frequency of resealing depends on factors such as weather exposure, the type of sealant used, and the age of the brickwork. Generally, exterior brickwork should be resealed every 3 to 5 years to maintain optimal protection, while interior bricks may require less frequent maintenance.

Final Thoughts

Masonry sealants offer invaluable protection for brickwork, preserving both its appearance and structural integrity. Whether you’re safeguarding an older home from moisture damage or maintaining a new brick facade, investing in the right sealant can help extend the life of your brickwork and reduce the need for costly repairs.

By choosing a quality masonry sealant and applying it correctly, you can enjoy beautiful, resilient brickwork that stands the test of time. If you’re unsure about the best approach for your brick structure, consulting a masonry professional can ensure that your sealant application is tailored to meet your specific needs.