How Do You Clean Brick Without Damaging the Mortar?
Brick survives pressure; the mortar between it often does not. High PSI erodes joints, and on older lime mortar it can wash them out entirely. Brick and stucco clean by soft washing — a low-pressure treatment that works into the porous surface and lifts growth without cutting the joints.
Why does pressure washing damage brick walls?
The brick is rarely the weak point — the mortar is. Mortar is softer than fired brick by design, so it can flex and take up movement, and that same softness means a concentrated jet cuts it. Run a pressure washer along a joint and you will lower it, sometimes visibly in one pass, and once the joint is recessed water sits in it instead of shedding off the wall.
The age of the house decides how bad this gets. Older Shoals homes were often laid with lime-based mortar, which is deliberately soft and can be washed out alarmingly quickly. Repointing a wall costs multiples of what cleaning it does, which makes brick one of the surfaces where method matters most.
Why does brick hold green growth so stubbornly?
Because it is porous. Brick and mortar both hold water in their surface, and that retained moisture is exactly what algae, moss, and lichen need. Growth on masonry is not sitting on top the way it does on glass — it is rooted into the surface, which is why scrubbing the visible green off a brick wall does so little and why it returns so fast.
Shaded, north-facing, and ground-level brick goes first. Anywhere a sprinkler hits the wall, a downspout empties nearby, or soil is banked against the brick will stay damp permanently and grow the heaviest, and no cleaning holds up well until that source is dealt with.
What about efflorescence — the white powder on brick?
That white bloom is efflorescence: mineral salts carried to the surface by moisture moving through the masonry, left behind as the water evaporates. It is not mould, it does not respond to the treatments that clear algae, and it will come back for as long as water keeps moving through the wall.
Which makes it a symptom worth reading rather than just cleaning off. Persistent efflorescence usually means moisture is getting into the masonry — a leaking gutter, a downspout discharging at the base, grade sloping toward the house, or a failed flashing. Clearing the deposit is straightforward; finding the water is the part that actually fixes it.
Can painted or sealed brick be cleaned the same way?
It needs more care, not less. Paint on brick is often already failing in places, and any cleaning will find those places — low pressure will lift what was barely attached, which is better discovered deliberately than as a surprise. Sealed brick is similar: the sealer is a coating, and coatings can be dulled or stripped.
Brick and stucco fall under soft washing, from $400, priced by wall square footage and condition. If the brick is painted, say so when you book, because it changes both the approach and what is realistic to expect — cleaning painted brick is about the paint, not the masonry.
Questions we hear about this
Can you pressure wash brick?
You can, and it is a common way to cause expensive damage. The brick usually survives; the mortar joints between it erode, especially the softer lime mortar in older Shoals homes. Repointing costs far more than cleaning, which is why brick is soft washed.
How much does brick cleaning cost?
Brick falls under soft washing, which starts from $400 and is priced by wall square footage and condition. We price your exact house at the walk-round.
What is the white chalky deposit on my brick?
Efflorescence — mineral salts brought to the surface by water moving through the masonry. It is not mould and it is not dirt. It cleans off readily, but it returns until the moisture source is found, so it is worth checking gutters, downspouts, and grade around the wall.
Will cleaning remove paint from my painted brick?
It will lift paint that is already failing. A low-pressure clean will not strip sound paint, but where the bond has gone the cleaning will find it. If the brick is painted, tell us when you book so we can set expectations before we start rather than after.