White powdery bloom on brickwork or new paving is efflorescence: salts already inside the material carried to the face by water and left there as it evaporates. It is not mould and it is not a cleaning failure.
Where the salt comes from
Cement, sand and some bricks contain soluble salts. New build and newly laid paving show it most, because there is still construction water working its way out.
This guide sits under our Wall Cleaning & Softwash work, covering 20-mile radius of Plymouth.
Why washing can worsen it
Soaking the wall dissolves more salt and carries it to the surface as it dries again. Repeated hosing can extend the bloom rather than end it.
The realistic approach
Dry brushing and patience deal with most of it as the material dries out over its first seasons. Where the source is persistent damp, the damp is the job, not the bloom.
Questions we get on this
- Will it go on its own?
- New-build efflorescence usually fades over the first year or two as the structure dries.
- Would you clean it for me?
- We will tell you honestly when the answer is to wait rather than pay us.
- Is it a damp problem?
- It can be, if it keeps returning in one spot years after construction. That is worth investigating.
Related reading
- New builds: what needs cleaning in the first five years
- Detached houses: planning a whole-property clean
- Estate agents and vendors: kerb appeal on a deadline
- Care homes, schools and community buildings