Home' Inclean : INCLEAN Jan-Feb 2016 Contents 38 INCLEAN January/February 2016
Here’s the bad news: efflorescence is
extremely difficult to resolve. There isn’t a
clear-cut solution to fix the problem, and no
solution is guaranteed.
There are a couple of steps you can take to
try and keep the problem under control:
1. Maintenance cleaning can remove
the salt crusts
Maintenance cleaning can be effective in
removing the crust of mineral salts from on
top of the surface.
This commonly entails acid washing on
internal areas (providing it’s not on acid-
sensitive stone), a specialist efflorescence
remover, or pressure washing on some
However this maintenance cleaning
won’t remove the source of the salts, so it’s
important to complete it regularly otherwise
the problem can reoccur.
2. Sealers can help minimise
If there’s no water, there’s no way for the
salts to travel, so they can’t evaporate to the
surface and create a crust. A high-quality
water-repellent sealer can help minimise
water reaching the substrate.
In these cases it’s important to choose the
best sealer possible, as it will be critical to
preventing future efflorescence crusting.
Be warned! Efflorescence is
a building defect
Efflorescence can be prevented by good
design and specification. As a result,
efflorescence is now generally recognised as
a building defect.
This makes it particularly important to
take steps to prevent it, rather than becoming
liable for the costs of replacement. (And
yes, it will almost always be replacement, as
guaranteed recovery just isn’t possible).
Unlike many other tile problems, it’s very
hard to tell whether efflorescence will
Efflorescence and mineral salts:
causes, solutions, and prevention
By Garry Phillips*
Efflorescence is a
pretty name for
a very unsightly
French for ‘to flower
out’, describing the
white salt coating
that spreads out from grout lines and other
fissures in the surface.
What causes efflorescence?
In simple terms, efflorescence is caused
by mineral salts. When water enters the
surface it dissolves the salts and as the water
evaporates it carries the salts to the surface
where it solidifies and creates a white or
It is uncommon for mineral salts to be
found inside the stone or tiles. More often
the salts are located in source material
such as screed used in the tile bed, which is
commonly made with unwashed sand.
However the presence of mineral salts in
the surface or substrate doesn’t guarantee
you’ll get efflorescence. It will only occur
in a wet area – most often outdoors, but
also in bathrooms, showers, and sometimes
kitchens if enough water is present.
Internally it’s a particular problem as the
salty efflorescence crusts can create an acid
reaction on sensitive stones such as marble
and limestone. This leaves the surface pitted
and eroded, requiring replacement of the
surface or major resurfacing even after the
efflorescence is removed.
affect a surface. Faultless tiling work and
good quality tiling materials are the only
ways to ensure that mineral salts won’t
affect your surface.
In ANY wet area surface, these are the
steps you should take in order to protect
your surface against efflorescence (and
protect yourself against the costs involved in
dealing with efflorescence!)
1. Always used washed sand
Really, this applies anywhere, whether wet
or dry. However it’s absolutely critical in
any area that will be exposed to the wet.
2. Use double waterproof membranes
Two waterproof membranes are better than
one. The extra membrane isolates the tile
surface from the cement screed.
3. Get good quality grout
Choose a grout system that is guaranteed by
the manufacturer to be salts-free. If it’s for
a high-risk environment (such as a shower),
consider using a fully waterproof grout such
as epoxy grout.
4. Use a sealer
If you want to be particularly cautious,
choose a sealer that is designed to remove
efflorescence prior to the tile laying.
However in most cases a good-quality
water-repellent sealer that is designed for
your surface will give you a final level
of protection. And it will keep your tiles
looking good, too.
It might cost a little more at installation
stage, but prevention is always much cheaper
than trying to remedy the problem afterwards.
*Garry Phillips is The Tile Expert
(www.thetileexpert.com); founder of Slique
International and Tile Cleaning Products
Efflorescence on stairs
down front of stair treads
Efflorescence on marble has
caused pitting from acid damage
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