Evansville Tuckpointing White powder on brick: what efflorescence is telling you about the wall
White chalky powder on brick or stone is efflorescence: salts carried out of the masonry by water and left on the surface when the water evaporates. The deposit is harmless. The message is not, because it means water is moving through the wall. In Evansville the usual sources are open mortar joints, a failed chimney crown, a leaking downspout, or a damp foundation wall, and the fixes run from a $0 downspout extension to a $10 to $25 per square foot foundation repoint.
Check this first (twenty minutes, dry day)
- Find the pattern. Efflorescence maps the water. A band across the bottom courses means ground moisture or splashback. A stripe means a downspout or a valley. A patch under a window means the sill. A whole chimney means the crown or the cap.
- Check inside on the same wall. Powder on the inside face of a basement wall, chalky lines on parged block, or salt on the floor at the base means water is coming through, not just soaking in.
- Brush a test patch. Dry brush with a stiff bristle brush, then wet brush. If it comes back after the next rain, water is still arriving. If it does not, you may have caught a one-off wetting event.
- Sound the joints beside it. Run a key along the mortar. Efflorescence plus crumbling joints is a repointing job, and the crumbling mortar page covers what that looks like.
- Walk the outside during rain. Two minutes in a downpour with an umbrella tells you more than an hour on a dry day. Watch where the gutters overshoot and where water lands next to the foundation.
What is usually wrong
| Where the powder is | Likely cause | Fix and cost |
|---|---|---|
| Bottom two or three courses outside | Splashback, grade sloping to the house, no downspout extension | Grade and drainage first, often little to no masonry cost |
| Inside a basement brick or stone wall | Water table and a wall with open joints | Foundation repointing, $10 to $25 per sq ft, typical $2,000 to $8,000 |
| Vertical stripe on an elevation | Downspout, gutter, or roof valley dumping on the wall | Fix drainage, then spot repoint $300 to $900 |
| Whole chimney above the roof | Cracked crown or missing cap letting water in the top | Crown $400 to $1,200, repointing $800 to $2,500 |
| Under a window sill | Sill cracked, or has lost its slope and drip | Sill repair or reset, $300 to $1,200 each |
| New bloom weeks after repointing | Normal new construction bloom | Dry brush, usually weathers away |
| Powder plus flaking faces | Salt crystallizing under the surface | Unit replacement $20 to $40 each plus the water fix |
Ranges are the ones on the pricing page. If the wall is a basement or foundation, start with foundation and basement wall repointing.
Why Evansville walls do this
Preservation Brief 2 describes the mechanism precisely: mortar historically acted as a bedding material rather than a glue, and moisture was meant to migrate out through the joints. When it evaporates it deposits soluble salts, either on the surface as efflorescence or below the surface as subflorescence. Salt crystallizing inside the unit creates pressure that can spall or delaminate the face. So efflorescence and spalling are two stages of the same process.
Evansville gives that process plenty to work with. Normal annual precipitation is 45.31 inches, with March at 4.60, April at 5.14, and May at 5.12. The city sits on the Ohio and has been above the 42-foot flood stage 41 times since 1940 according to the Evansville Levee Authority, and the older neighborhoods along the river and Pigeon Creek have brick and stone foundations sitting in soil that stays wet. Then roughly 77 freeze-thaw cycles a winter, from 92.6 nights a year at or below 32 degrees against only 15.5 days that stay frozen, drive the water in and out of the joint. A basement wall showing a chalk line at the same height every spring is telling you where the water table gets to.
When it is structural, not cosmetic
Powder alone is cosmetic. It becomes a repair when the joints beside it have gone soft, when the brick faces have begun to flake, when a whole basement wall is damp to the touch through the season, or when the deposit keeps returning after cleaning, which means the water path is open and working. Flaking faces are on the spalling brick page, and a basement wall actually passing water is on the water through a basement wall page.
What to expect on the call
Photograph the outside elevation, the same wall from inside if it is a basement, the gutters and downspouts above the affected area, and the chimney if the deposit is high on the wall. The first answer you should get is where the water is coming from, and the cheapest fixes are often not masonry at all. When repointing is the answer, ask for grind depth, mortar type, and joint profile in writing, and do not let anyone seal or paint the wall to hide it, because a coating traps the moisture that the salt is riding on.
Frequently Asked Questions
Is white powder on brick harmful?
The deposit itself is harmless salt. What it tells you is not. Efflorescence means water is moving through the masonry, dissolving salts, and evaporating at the surface. When those salts crystallize just under the surface instead of on it, the pressure spalls the face off the brick, which is how a cosmetic stain becomes a $20 to $40 per brick repair.
How do I get efflorescence off brick?
Dry brush it first with a stiff natural or nylon bristle brush, then wet brush. Preservation Brief 2 says muriatic acid is generally ineffective on efflorescence and should not be used, because it can liberate more salts and cause more bloom. Cleaning without fixing the water source just means it returns after the next wet spell.
What does it cost to fix the cause of efflorescence in Evansville?
It depends where the water is coming in. Repointing open joints runs $8 to $20 per square foot, a basement or foundation wall repoint is $10 to $25 per square foot with typical jobs at $2,000 to $8,000, a chimney repoint is $800 to $2,500, and a crown replacement is $400 to $1,200. Free-standing fixes like a downspout extension cost nothing and often do the most.
My new masonry has white bloom on it. Did something go wrong?
Probably not. Preservation Brief 2 notes that new construction bloom appears within the first few months after repointing and usually weathers away on its own. If it is still coming back a year later, or it is heavy in one spot, then there is a water path worth chasing.