“Brick sealer” is a term that gets tossed around a lot these days, but many people are still unsure what it actually means, what it does, and whether they need one. At The Pressure Cleaning Guys, our Perth-based team of experts has helped countless homeowners protect their brick and masonry surfaces with long-lasting, high-performance sealing services.
Here’s your go-to guide to understanding brick sealers and how they can protect your home’s exterior.
What Is a Brick Sealer, Exactly?
A brick sealer, also called a masonry sealer or brick sealant, is a type of liquid treatment applied to outdoor brick walls, render, concrete, and other porous masonry surfaces to create an invisible, water-repellent barrier. This barrier helps prevent water, stains, grease, and contaminants from soaking into the material, reducing long-term damage and keeping your brick wall looking clean and sharp.
Brick sealer products come in both water-based and solvent-based options and are usually easy to apply using a brush, roller, or garden sprayer. They soak into the surface and work by chemically bonding within the pores of the brick or render, helping to repel water while allowing water vapour to escape. This is key for maintaining a breathable surface that doesn’t trap condensation.
For tailored advice on your surface, whether it’s brick, blockwork, concrete or mortar, reach out to our team at The Pressure Cleaning Guys.
What’s the Difference Between Penetrating Sealer and Film-Forming Sealers?
There are two main types of sealers: penetrating sealers and film-forming sealers. Both protect the surface, but they work differently.
Penetrating sealers soak into the porous surface, creating a breathable, hydrophobic barrier within the brick or masonry. They provide a natural finish and won’t change the appearance of the material. These are ideal for homeowners who want invisible protection without a glossy sheen.
Film-forming sealers, on the other hand, create a visible coating on top of the surface, often with a matte or glossy finish. While they offer more resistance to stains and contaminants, they can darken the brick slightly and usually need reapplication more often.
Professionals often recommend premium penetrating sealers for long-term performance, especially in Australian climates where UV and rain exposure are high.
How Long Does a Brick Sealer Last Outdoors?
The lifespan of a brick sealer depends on the product type, the condition of the surface, and environmental exposure. In general:
- High-quality penetrating sealers can last up to 10 years or more.
- Film-forming sealers typically last 1–3 years before needing a fresh coat.
A good sealer protects against UV, water absorption, spalling, and other forms of deterioration, but regular inspections and maintenance are key. Reapplying sealer when you notice water stops beading on the surface helps maintain strong repellent properties.
What Happens If You Don’t Seal Brick Surfaces
It’s a common myth that bricks are naturally waterproof. In reality, brick and masonry surfaces are porous and will absorb water if left unprotected. This can lead to a number of issues:
Damp and condensation issues: When water penetrates the surface, it can seep into walls, especially if insulation or mortar is poorly installed. This creates internal dampness and contributes to mildew and condensation.
Freeze-thaw damage: When absorbed water freezes, it expands and causes cracking or spalling. Over time, this leads to deterioration and damaged brick faces.
Salt efflorescence: That white powdery coating on brick? It’s caused by salts pushed to the surface as water evaporates. While mostly cosmetic, it’s a sure sign your wall is absorbing too much water.
Aesthetic damage: Algae, lichen, and other green growth thrive on damp brick, especially in shaded areas. Aside from being unsightly, this biological growth can accelerate surface decay and make the wall look stained and tired.
To avoid issues like these, hiring pros like The Pressure Cleaning Guys ensures the job gets done right, using the best brick sealer for your surface type and local conditions. Explore all our pressure cleaning and sealing services to see how we can help protect your home.
What Makes Our Brick Sealer Different at The Pressure Cleaning Guys?
Our team of experts use a high-performance, superhydrophobic brick sealer that penetrates deep into masonry surfaces, reaching up to 17mm. Unlike film-forming products, our sealer becomes part of the substrate, allowing the wall to breathe while completely repelling water.
This is known as the lotus effect, where water beads and rolls off the surface, taking dirt and grease with it. It’s perfect for keeping your walls clean with minimal effort.
Tested under extreme weather simulations for 25 years by Lucideon (a UKAS-accredited lab), our sealer:
- Reduced water absorption by 96.3%
- Kept treated brick walls on average 6°C warmer than untreated ones (thermal benefit)
- Retained breathability with an SD value of 0.56, meeting the breathable coating standard
- Showed no visual degradation throughout the test
Our sealer has also been validated by the Energy Saving Trust for its thermal performance, helping homes retain heat more efficiently in the winter and lowering energy bills.
How Sealers Protect Brick and Concrete
Brick and concrete sealer products typically cure through a process called cross-linking: a chemical reaction that forms a tight, durable network as the product cures. This cured barrier helps prevent deterioration caused by water ingress, UV exposure, grease, and airborne contaminants.
Whether you’re sealing a brick wall, a render surface, or a paved area, the right sealer protects your investment by increasing surface strength, reducing stain risk, and extending the life of the material.
Thinking of DIY Sealing?
If you’ve picked up a brick sealer from your local hardware store and want to give it a go yourself, here’s a guide.
You’ll need:
- A brick sealer
- Paint tray
- Long-pile roller or paintbrush
- Dust brush
- Sandpaper
- Dust sheets
- Masking tape
- Optional: low-pressure sprayer
Preparation:
Start by cleaning the surface. Use a stiff brush to remove moss, algae, or efflorescence. If the wall is painted, you’ll need to strip it first, as the sealer is only for bare masonry surfaces. For biological contamination, use an anti-fungal cleaner and allow it to sit for 3 hours before rinsing thoroughly.
Fill any cracks or holes with exterior-grade filler, sand smooth, and tape off windows, doors, or areas you don’t want to coat. Lay down dust sheets to protect the ground.
Application:
Wait for a dry day above 5°C. Apply the sealer evenly using a roller, brush, or sprayer. The consistency is thicker than paint, so you’ll want to apply a light but complete coat. One coat is typically enough.
Within 2 hours you’ll start to see water bead on the surface. Full curing takes over 24 hours. Once there’s no white powdery residue, the sealer has fully bonded to the surface.
Not keen on spending your weekend sealing bricks?
If the job sounds a bit messy or more effort than it’s worth, leave it to the pros. Call The Pressure Cleaning Guys and we’ll get it done efficiently and with a top-quality finish.
Frequently Asked Questions
What surfaces can you apply brick sealer to?
Brick sealer can be used on most porous surfaces, including brick, stone, concrete, sandstone, limestone, and mortar. It penetrates the surface to create a waterproof barrier.
Will sealing my bricks change the way they look?
No. Our brick sealer leaves a natural finish with no shine or darkening. It won’t give your wall a wet or glossy look.
Can I paint over sealed brick?
It is not recommended to paint over sealed brick. Once the surface is sealed, paint won’t stick properly. If you want colour, use a breathable, waterproof masonry paint instead. You also can’t seal over existing paint, as the sealer needs to penetrate the raw brick.
How long does brick sealer last?
Some sealants can wear off in under five years. Our sealer at The Pressure Cleaning Guys has a 25-year proven track record and often lasts much longer. That’s why it comes with a lifetime warranty.
How much sealer do I need?
Coverage depends on your surface type, but our sealer typically covers 3–5m² per litre. For a 40m² wall, you’ll need about 10 litres. It’s a one-coat application, so no need for extra layers.
How do I clean up after applying sealer?
Wipe up any spills straight away with a dry cloth. If it dries, use mineral spirits to break it down and scrub gently with soap and warm water. Always follow the product instructions.
