Maintaining the structural integrity of brickwork often requires understanding how environmental factors impact its longevity. Penetrating sealers, a crucial element in brick maintenance, offer significant protection against water damage, one of the primary threats brick faces. Silane and Siloxane based formulations are a popular choice for homeowners, providing a breathable barrier. Selecting the appropriate outdoor sealant for brick is essential, and a proper application will help preserve the aesthetic appeal and the structural reliability of your brick surfaces for the future.

Image taken from the YouTube channel DIY Gardening , from the video titled Brick Sealer/Waterproofer Comparison .
Brick Savior: Choose the Best Outdoor Sealant!
This guide will help you navigate the world of outdoor sealants for brick, ensuring your brickwork remains beautiful and protected from the elements for years to come. We’ll cover the factors to consider when choosing a sealant, the different types available, application tips, and maintenance best practices.
Understanding the Importance of Outdoor Sealant for Brick
Brick, while durable, is a porous material. This means it readily absorbs water, which can lead to a host of problems:
- Freeze-Thaw Damage: Water trapped inside brick expands when it freezes, causing cracks and spalling (flaking). This is a major concern in climates with freezing temperatures.
- Efflorescence: Water carries salts to the surface of the brick, leaving unsightly white deposits.
- Mold and Mildew Growth: Damp brick provides a perfect breeding ground for mold and mildew, which can stain and damage the brick.
- Structural Degradation: Over time, water damage weakens the structural integrity of the brickwork.
Using an appropriate outdoor sealant for brick prevents these problems by creating a protective barrier against water intrusion.
Key Considerations When Choosing an Outdoor Sealant
Selecting the right sealant involves evaluating several factors:
- Type of Brick: Different types of brick have varying levels of porosity. Older, softer bricks often require a more breathable sealant.
- Climate: Consider your local climate. Areas with heavy rainfall or extreme temperatures require more robust sealants.
- Desired Appearance: Sealants can be invisible, enhance the brick’s color, or create a glossy finish. Choose one that matches your aesthetic preferences.
- Breathability: A breathable sealant allows water vapor to escape from the brick, preventing moisture buildup and potential damage. This is especially important for older brickwork.
- Durability and Lifespan: How long will the sealant last before needing reapplication? Look for products with a long lifespan and UV resistance.
- Ease of Application: Consider your DIY skills. Some sealants are easier to apply than others.
- Coverage Area: How much area will the sealant cover per gallon or container? Calculate this to ensure you purchase enough product.
Types of Outdoor Sealants for Brick
Several types of sealants are available, each with its own advantages and disadvantages.
Siloxane Sealants
- Characteristics: Highly breathable, water-repellent, and long-lasting. A popular choice for brick.
- Pros: Excellent breathability, good water resistance, long lifespan (5-10 years), often invisible finish.
- Cons: Can be more expensive than other options, may require professional application for optimal results.
Silane Sealants
- Characteristics: Similar to siloxane sealants, but with smaller molecules that penetrate deeper into the brick.
- Pros: Excellent penetration, good water resistance, long lifespan (5-10 years), often invisible finish.
- Cons: Can be more expensive than other options, may not be as effective on heavily damaged brick.
Acrylic Sealants
- Characteristics: Water-based, easy to apply, and affordable.
- Pros: Easy to apply, affordable, good for minor water resistance.
- Cons: Less durable than siloxane or silane sealants, may not be as breathable, shorter lifespan (1-3 years).
Polyurethane Sealants
- Characteristics: Creates a tough, durable, and waterproof barrier.
- Pros: Excellent water resistance, durable, can be used to fill small cracks.
- Cons: Not breathable, can change the appearance of the brick, may yellow over time, more difficult to apply.
Choosing the right type depends on your specific needs and the condition of your brick.
Application Tips for Outdoor Sealant
Proper application is crucial for the sealant to perform effectively.
- Preparation is Key:
- Clean the brick thoroughly using a brush and a mild detergent solution.
- Remove any loose mortar or debris.
- Repair any cracks or damage before applying the sealant.
- Allow the brick to dry completely before applying the sealant.
- Choose the Right Weather Conditions:
- Apply the sealant on a dry day with temperatures between 50°F and 80°F (10°C and 27°C).
- Avoid applying sealant in direct sunlight or when rain is expected.
- Apply the Sealant Evenly:
- Use a brush, roller, or sprayer to apply the sealant according to the manufacturer’s instructions.
- Apply thin, even coats to avoid drips and runs.
- Pay attention to mortar joints, as they are often more porous than the brick itself.
- Allow Adequate Drying Time:
- Allow the sealant to dry completely before exposing the brick to water.
- Follow the manufacturer’s instructions for drying time, which can vary depending on the product.
Maintenance and Reapplication
Even the best outdoor sealant for brick will eventually need reapplication.
- Regular Inspections: Inspect your brickwork annually for signs of damage, such as cracks, spalling, or efflorescence.
- Cleaning: Clean the brick regularly with a mild detergent solution to remove dirt and debris. Avoid using harsh chemicals or abrasive cleaners.
- Reapplication: Reapply the sealant as needed, typically every 1-10 years, depending on the type of sealant and the severity of the weather. Consult the product manufacturer for specific recommendations.
By following these guidelines, you can choose the best outdoor sealant for brick and protect your brickwork for many years to come.
Brick Savior: Outdoor Sealant FAQs
This section answers common questions about choosing the right outdoor sealant for brick projects.
Why is it important to seal outdoor brick?
Sealing brick helps protect it from water damage, freeze-thaw cycles, and staining. An effective outdoor sealant for brick will extend the life of your brickwork and keep it looking its best.
What type of outdoor sealant should I use on brick?
Penetrating sealants, like silanes or siloxanes, are generally recommended. They soak into the brick and create a water-repellent barrier without changing the brick’s appearance. Avoid film-forming sealants, as they can trap moisture and lead to cracking. Choose an outdoor sealant specifically designed for brick.
How often should I reapply an outdoor sealant to my brick?
Reapplication frequency depends on the product and the environment. Most outdoor sealants for brick need reapplication every 3-5 years. Always check the sealant manufacturer’s instructions for the recommended schedule.
Can I apply an outdoor sealant to wet brick?
No. The brick must be completely dry before applying an outdoor sealant. Moisture trapped beneath the sealant can cause damage and reduce its effectiveness. Allow sufficient drying time after cleaning or rain before application.
So, go ahead and find the perfect outdoor sealant for brick! Your brickwork will thank you. Best of luck with your project!