How to Protect Your Bricks From Freeze-Thaw Damage This Winter

Brick homes and brick walls look beautiful, but winter can be tough on them, especially when NYC temperatures jump above and below freezing (from around a high of 4°C (39°F) and often fall below 0°C (32°F)). That freeze-thaw cycle is the biggest enemy of bricks. Water gets inside tiny cracks, freezes, expands, and slowly pushes the bricks apart. If you’ve ever seen crumbling mortar, flaking brick surfaces, or walls that look worn out after winter, that’s usually freeze-thaw damage at work. These issues are also part of common weather damage on brick walls, which can worsen without proper maintenance

The good news? You can prevent most of this damage with a few simple steps. Brick is a strong material, and when it’s properly protected, it can last for generations. The key is keeping water out and helping your bricks breathe.

Below is your complete guide to protecting your brickwork this winter.

Seal and Repair the Bricks

Winter damage starts long before the first snow falls. It begins when water sneaks into cracks, pores, and weak mortar joints. Once water gets in, freezing temperatures turn it into ice, and the expanding ice slowly breaks down the wall.

That’s why the first big step in protecting your brickwork is sealing it and repairing anything that might let moisture in with the help of professional masonry contractors. 

Apply a Breathable Sealant

Think of a sealant as a waterproof jacket for your bricks. It keeps rain and snow from soaking in, but a good one still lets the wall “exhale.” Bricks naturally hold some moisture, so if you trap that moisture inside with the wrong sealant, the wall can actually get damaged faster.

A breathable, water-repellent sealant, such as Hydra sealants, and penetrating sealers like those based on silanes, siloxanes, and silicon. They line the pores of the material with a hydrophobic barrier, which helps stop new water from entering while letting old moisture escape safely. That’s exactly what you want for winter.

Use a Quality, Breathable Product

Not all sealants are the same. Some are thick, glossy coatings that trap moisture inside the wall, so you should avoid those. You want something made specifically for masonry. Brick sealants should be breathable, water-repellent and specifically designed for exterior masonry. 

Below are some of the effective products:

• Silane/Siloxane Sealers: Highly effective breathable sealers that penetrate deeply and form a long-lasting, invisible moisture barrier without creating a surface film.
• DryWay Water Repellent Sealer: Water-based silane–siloxane blend designed for deep penetration and durable protection on concrete and masonry.
• Smartseal Brick Sealer: Clear, solvent-free, breathable impregnating sealer suitable for brickwork, masonry, and exterior facades.
• PENTREAT 244-40 W/B: High-performance penetrating silane sealer that protects concrete and masonry from moisture intrusion and de-icing salt damage.
• PermaSEAL Facade Cream / Microshield PRO: Masonry creams that absorb into the substrate, lining pores to create a water-repellent but highly breathable finish.
• Sika Water Seal: Solvent-based penetrating water repellent that maintains surface breathability while providing strong moisture resistance.
• Silicone-Based Sealers: Formulations designed for high breathability, ideal for heritage structures where moisture transfer must remain unobstructed.
• Hydra Sealant: Transparent, breathable sealant that effectively repels water while allowing internal moisture vapor to escape.

A high-quality product might cost a bit more, but it can protect your home for years, even through harsh winters.

Seal Existing Cracks Before Sealing the Whole Wall

Before you apply a sealant to the whole surface, you need to repair the cracks you can see. Even the tiniest crack can let water in, and once freezing temperatures hit, that little crack becomes a much bigger one.

Use a masonry-grade crack sealant to fill:

• Gaps
• Fine cracks
• Small holes
• Separation lines in mortar

When you seal these openings before applying the main waterproofing layer, you stop water from entering the areas where it can do the most damage.

Maintain the Mortar (Repointing)

Mortar is the glue between your bricks. When it weakens, cracks, or crumbles, water can run right through it. Freeze-thaw cycles hit mortar even harder than brick, so checking it before winter is essential.

If you see mortar that looks loose, dusty, or missing in spots, it’s time for repointing, which is a process where old mortar is removed and replaced with fresh material. Repointing not only strengthens the wall but also closes gaps water loves to sneak into.

A solid, well-maintained mortar joint is one of the best defenses against winter damage.

Manage Water Drainage

Even the best sealant can’t protect your bricks if water is constantly flowing toward your home or pooling around your foundation. Drainage plays a huge role in brick health, especially during winter. Standing water equals more freeze-thaw cycles. More freeze-thaw cycles equal more damage.

Here’s how to make sure water stays far away from your brick walls.

Clear Gutters and Downspouts

If your gutters are stuffed with leaves or the downspouts are clogged, water has nowhere to go. Instead, it spills over the edge and runs straight down your walls. That water soaks the brick, freezes overnight, and slowly begins to damage the structure.

Before winter hits:

• Clean out leaves
• Remove nests and debris
• Flush the downspouts
• Make sure water flows freely

A clean gutter system helps your bricks stay dry even during snowmelt and heavy rain.

Improve Ground Grading

Take a slow walk around your house and look at the soil near the foundation. Does the ground slope toward your home or away from it? If it tilts inward, water will naturally pool near your walls every time it rains.

The goal is to make sure the soil slopes gently away from the house. This simple change keeps standing water away from brick walls and foundations, reducing the chances of freeze-thaw damage.

Extend Downspouts

Even if your gutters work properly, downspouts that dump water right next to your home can still cause problems. A basic rule is to extend them 6 to 10 feet away from the foundation.

This sends water safely away from bricks, patios, pathways, and basement walls. Downspout extensions are cheap, easy to install, and incredibly effective.

Additional Tips

You’ve already tackled sealing, repairing, and drainage, which are the three biggest factors in protecting bricks from winter damage. Here are a few more tips that help keep your brickwork in great shape all season long.

Avoid Excessive De-icing Salts

Salt may melt ice, but it isn’t friendly to bricks. Too much de-icing salt can:

• Wear away the brick surface
• Damage mortar
• Leave behind chemicals that speed up deterioration

If you need to use salt, choose plant- and pet-friendly options and apply them lightly. Once the ice melts, sweep up leftover granules immediately so they don’t soak into the surface.

Monitor the Sealant

Sealants don’t last forever. Over time, sunlight, rain, and winter weather wear them down. A quick way to test the sealant is simple: splash a little water on the brick surface. If the water beads up, your sealant is still doing its job. If it absorbs or darkens the brick, it’s time to reapply.

A fresh sealant every few years can make a huge difference in preventing freeze-thaw damage.

Consider Professional Help

If you’re unsure which sealant to use, how to repair mortar, or whether your wall is already damaged, don’t hesitate to call a professional mason. Brick specialists have the tools and experience to assess your situation and make sure your home is protected before temperatures drop.

Sometimes, spending a little on expert advice saves you from spending a lot on repairs later.

Conclusion

Freeze-thaw cycles can be tough on brick walls, but the damage isn’t inevitable. With the right care, from sealing and repairing cracks to maintaining mortar and managing drainage, you can protect your bricks and keep them strong for many winters.

Winter only becomes a problem when water finds its way into brick surfaces. If you block that path, the cold can’t do much harm. A breathable sealant, solid mortar joints, clean gutters, and good grading go a long way in keeping your home safe, warm, and damage-free. By taking these steps now, you’ll help your brickwork stand tall through freezing nights, snowstorms, and spring thaws. And when winter finally ends, your walls will look just as solid and beautiful as they did before the first snowfall.

Need help protecting your brick walls this winter? Contact us for a free inspection and expert guidance.