What We Fix
What We Fix
Salt Attack
Is salt attack damaging my brickwork?
You've noticed bricks crumbling at the base of your walls. White, chalky deposits on the surface. Mortar joints turning to powder between your fingers. Maybe the render has cracked and blown off in patches. You might have already repointed or replastered — and it came back worse.
The bricks aren't the problem. The salt inside them is. When moisture enters masonry — from the ground, from coastal spray, from poor drainage — it carries dissolved salts deep into the brick and mortar. As the wall dries, those salts crystallise and expand inside the pores of the masonry. That expansion is powerful enough to fracture brick from within. The technical term is spalling — and once it starts, every wet-dry cycle makes it worse.
The signs below will help you work out if salt attack is what's destroying your brickwork — and where the salt is coming from.
What are the symptoms of salt attack?
Not every crumbling brick is salt attack. These are the signs that confirm it.
White Deposits on Brickwork (Efflorescence)
White, chalky deposits on the face of your bricks or render are salt crystals — called efflorescence. As moisture moves through the wall and evaporates at the surface, the salts it carried are left behind. Light efflorescence can be brushed off, but if it keeps returning, the salt attack is working from inside the masonry where you can’t see it.
Crumbling or Spalling Bricks
When salt crystallises inside the pores of a brick, it expands with enough force to fracture the surface. The face of the brick cracks, flakes, and eventually crumbles away — a process called spalling. Once the protective outer face is gone, moisture penetrates deeper and the cycle accelerates. Spalling bricks at the base of walls are one of the clearest signs of salt attack.
Mortar Joints Falling Apart
Mortar is softer and more porous than brick, so it’s often the first material to fail. Salt crystals form inside the mortar joints and push them apart from within. The mortar turns sandy, recedes behind the brick face, and eventually falls out in chunks. Repointing without stopping the salt attack is a temporary fix — the new mortar will fail the same way.
Paint Flaking at the Base of Walls
Paint that blisters, flakes, or turns powdery near the base of your walls is a surface symptom of what’s happening inside the masonry. Salts crystallise behind the paint film and push it off the wall. Repainting without addressing the salt source will only hold for a few months before the same damage reappears. The salt doesn’t stop because the wall looks fresh.
Render Cracking and Blowing Off
When salts crystallise between the render and the brick, they create pressure that separates the two layers. The render sounds hollow when tapped, cracks in map-like patterns, and eventually blows off in sheets. This is called delamination. Re-rendering over active salt attack traps the problem behind a new surface — and the new render will fail the same way.
What are the signs of salt attack?
How to stop salt attack
Stop the Moisture. Stop the Salt.
Identify the Source. Fix It Permanently.
Salt attack is a damage mechanism, not a single problem with a single fix. The salts destroying your brickwork need moisture to move — without it, they stay dormant. Stop the moisture source and you stop the salt cycle. That's why the first step is always identifying where the moisture is coming from.
When rising damp is the source of the salt attack, DampBlock™ AQ50 is injected into the mortar course at the base of the wall through small holes drilled at close intervals. The resin spreads through the masonry and cures to form a permanent damp proof course — a brand-new DPC, without removing a single brick. Non-toxic, completely odourless, and most treatments are completed in a single day.
When the salt source is drainage, contaminated fill, or coastal exposure, the fix targets that specific cause — redirecting water, replacing fill, or protecting the masonry from further salt ingress. The free assessment identifies which scenario applies to your property and maps the full extent of the damage.
Once the moisture source is cut off, the wall dries out naturally. The salt crystallisation cycle stops. No more spalling, no more crumbling mortar, no more replastering every few years. The masonry stabilises and the damage stops progressing.
Structural Engineers · Licensed Builders · Skilled Technicians
Help & Advice
Articles to help you understand salt attack and what to do next.
Rising DampSalt Damp and Exploding Bricks
If you live in a home with walls constructed of porous masonry, you may have heard of, or even experienced rising damp. Just in case you haven't, it's where your brick, stone, marble, limestone or concrete walls have soaked up water out of the ground over time.
Rising DampWhat Is a Damp Proof Course?
A damp proof course (DPC) is your home's first line of defense against rising damp, stopping moisture from creeping up through porous masonry walls. But when it fails, trouble starts—yellow stains, peeling paint, salt deposits, and rotting skirting boards are all warning signs.
Rising DampHow to Stop Rising Damp in Your Home
If a wall has rising damp, paint won't fix it. Ventilation won't fix it. A dehumidifier won't fix it. None of those touch the cause.
Rising DampWhy Your Damp Proof Course Has Failed
A damp proof course, also known as a damp proof membrane, is a form of moisture control for your home. Commonly made of bitumen, plastic, slate or tin, they stop moisture from travelling into porous masonry.
Wall CracksHow to Repoint a Brick Wall
When the mortar joints between the bricks in your home begin aging, they crumble and crack. Repointing is something you can do yourself. Here’s our step-by-step guide.
Common questions about salt attack
The questions homeowners ask us most often.
