Efflorescence: the white chalky stain on brick, block, and concrete
It is salt. Water moving through masonry dissolves the soluble salts inside it, carries them to the surface, and evaporates, leaving the salt behind as a white bloom. That means efflorescence is a moisture symptom, not a cleanliness problem, and cleaning it without changing the water is why it keeps coming back.
- It comes from inside the wall, not off the air
- Pressure washing feeds the mechanism that causes it
- Recurrence is a water problem, not a cleaning failure
Thank you!
Someone from our team will reach out to you shortly.
Salt on its way out of the wall
Brick, block, mortar, stucco, and concrete all contain soluble salts. They are a normal part of the material. Efflorescence happens when water gets into the masonry, dissolves those salts, and then migrates back toward the surface as the material dries. The water evaporates at the face of the wall and the salt it was carrying is deposited there as a white, chalky, slightly crystalline bloom.
Three things have to be true at once for it to appear: soluble salt in the material, water to dissolve it, and a path to the surface. That is why it is a symptom rather than a stain. You are not looking at something that landed on the wall, you are looking at evidence that water is moving through it.
New masonry commonly blooms in its first year and then stops, because the construction moisture is working its way out and the readily soluble salt is finite. That kind is a nuisance and it self-limits. Efflorescence that keeps returning on the same patch of an older wall is telling you something different, and it is worth listening to before you pay anyone to scrub it off again.
The three ingredients
- Soluble salts inside the masonry
- Water moving through the material
- Evaporation at the surface
- Remove any one and it stops
- Cleaning removes none of the three
Six things that look like efflorescence and are not
Mold and mildew
The one people fear. Efflorescence is white to off-white, dry, powdery, and appears on masonry. Mildew is usually green, gray, or black, feels different, and prefers shaded and damp elevations. Efflorescence is not a biological growth and is not a health issue.
Hard water scale
Looks similar and forms by the opposite route. Scale lands on the wall from sprinkler overspray and dries there. Efflorescence comes out from inside. If the pattern matches a sprinkler arc, read our page on hard water stain removal instead.
Lime run and calcium leaching
A harder, glassier deposit, often running in streaks from a joint or a crack. It has already reacted and turned insoluble, and it does not respond to the treatment ordinary efflorescence responds to. This one is genuinely difficult.
De-icing salt residue
On driveways and garage aprons through a Utah winter, what looks like efflorescence is often just the road salt you drove home. It rinses off and it is a different conversation from salt emerging out of the slab.
Paint and sealer failure
A whitish blush in a coating, from moisture trapped behind it or a sealer that has gone milky. The wall underneath may be fine. Cleaning the surface does nothing, because the problem is in the film.
Mortar smear
On newer brickwork, residue left by the mason. It is in the same color family and gets blamed on efflorescence constantly, but it is construction residue and comes off with a different approach.
Why pressure washing usually makes it worse
The instinct is to blast it, and it half works, which is the trap. High pressure and a lot of water do take the visible bloom off. They also drive a significant volume of water straight into the porous material you just established has a water problem. That water dissolves more salt, and as the wall dries over the following days the bloom comes back, often heavier than before.
There is a second version of the same mistake. Wetting efflorescence redissolves it, so a wall can look completely clean while it is still damp and then dry white again within a day or two. People conclude the cleaning failed. What actually happened is that the salt was never removed, it was just temporarily put back into solution and left in place.
The right sequence starts dry. As much of the deposit as possible is removed mechanically with a stiff brush before any liquid touches it, because everything taken off dry is salt that can never be redeposited. Only then does a masonry cleaner go on, at the lowest strength that works, with a careful and complete rinse. On stucco and older mortar this is a soft wash problem, not a pressure problem.
Order of operations
- Dry brush first, always
- Lowest effective cleaner strength
- Test patch on an unseen elevation
- Full neutralizing rinse
- Assess again once genuinely dry
The part that is not cleaning
Find where the water is getting in
Downspouts discharging against the wall, grade sloping back toward the house, a failed sealant joint, sprinkler spray hitting masonry, a planter bed holding moisture against brick. It is usually visible in ten minutes once you are looking for it.
Fix the water before you pay for cleaning again
If the moisture path stays open, the bloom returns and you have bought a season. We would rather say that up front than clean the same wall twice a year. Sometimes that means the useful job is not ours.
Give new masonry time
First-year efflorescence on new brick or block is usually construction moisture leaving. It often resolves on its own, and aggressive early treatment can do more harm than waiting a season.
Then clean it, and consider sealing
Once the water is handled, removal is straightforward and lasting. A breathable masonry sealer can help afterwards, though a sealer applied over an active moisture problem traps it and makes things worse, so the order matters. Our cost page has starting prices, and house and masonry work is quoted under soft washing.
5.0 from 15 verified Google reviews
Real reviews from recent Dirt Gone Wash Co customers.
"Saya came to do my siding and back patio. He gave me a great deal! He was professional and reliable and had a great price compared to others I received. I highly recommend."
Carrie A. · Google review
"Saya came out and cleaned my trash bins and driveway, and I was really impressed with the results. He was honest from the start and explained that the oil stains on my driveway would need a hot water treatment to fully remove them."
Irma B. · Google review
"They do a very good job and I'm very impressed with their work. Super professional, 10/10 recommend!"
Tiana I. · Google review
Efflorescence questions
What is the white powder on my brick?
Is efflorescence mold?
Will it come back after cleaning?
Can you just pressure wash it off?
Is efflorescence a structural problem?
My house is new construction and the brick is blooming. Is that a defect?
Do you treat this on retaining walls, pavers, and block?
Where we work
Dirt Gone Wash Co. is a service-area business covering the corridor from Salt Lake City through Davis County to Ogden. Pick your city for local pricing and conditions.
Send a photo of the wall
We will tell you whether it is efflorescence, what it will take, and whether something has to change first.