▽ +09.00Problem · Concrete & walls
White salts on walls and concrete
White powdery or crusty deposits on concrete, masonry or tiles that come back after cleaning.
What you see
- White powder or crust on walls, floors or grout
- Deposits that return after cleaning
- Paint or plaster pushed off
- Stains along cracks and joints
Possible causes
Water moving through the material
It dissolves salts and leaves them on the surface as it evaporates.
Salts in the materials or the soil
In the cement, sand, water or ground.
Missing or failed waterproofing
A constant moisture source keeps the cycle going.
New construction drying out
Often temporary while the building dries.
How it is diagnosed
The diagnosis confirms the cause before any repair is chosen.
Does it recur?
One-off deposits on new work, or continuous growth?
Find the moisture source
The roof, the ground, tanks, wet areas or pipes.
Check for damage
Spalling or crumbling means salts are crystallising inside the material.
Possible solutions
The fix follows the diagnosis; these are the common options and their systems.
Stopping the water
Waterproof the source: the roof, the basement or the wet area.
Cleaning and repair
Dry brushing and suitable cleaners, then repairs.
Systems
Breathable protection
Coatings that let water vapour out.
Systems
What not to do
- Washing repeatedly with water
- Painting over the salts
- Using strong acids without advice
General educational content; final values and requirements follow the manufacturer’s TDS and the approved project specification.
Common questions
Is efflorescence harmful?
The deposit itself is mostly cosmetic, but it shows water moving through the structure, and its source must be found.
How is efflorescence removed and prevented?
It is brushed off dry, then cleaned with a suitable cleaner tested on a small patch first. It is prevented by stopping the water source first — waterproofing, joints, rising damp from the ground — then a water-repellent treatment where needed.
Technical inspection
Need a diagnosis for your case?
Send photos, a description and the location; our engineers identify the cause and the fix after an inspection.