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Efflorescence
is often described as a white or ivory chalk-like
deposit. Efflorescence is formed by water migrating
through the masonry wall and out the pores. As it passes
through the wall, it collects loose salt and lime and brings
them to the surface. As the water evaporates, the salt
or lime particles bond to the wall causing white stains.
Several products
can be used to remove efflorescence. NMD
80 at a (4:1) dilution. When using NMD 80
for post construction cleaning, removing mortar smears, NMD 80
will not cause or create efflorescence.
EF-Fortless
(undiluted) is formulated for one purpose which is to remove
efflorescence (calcium chloride). EF-Fortless is a soap
solution that counteracts efflorescence.
Not every
"white deposit" on a wall is efflorescence!
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Calcite
(calcium carbonate) will appear as a thick whitish deposit
that usually forms over time. Calcite most commonly
forms when excess moisture passes through the mortar
joints, evaporating leaving behind white deposits on clay
brick. For removing calcite from clay brick, use Calcite
Presoak (ON CLAY BRICK ONLY) followed by
NMD 80. For removing calcite from concrete masonry
units (CMU) use White
Scum Presoak followed by NMD 80.
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Lime Run
(calcium hydroxide) occurs as a steady release of calcium
soaked water that creates a streak. Generally, lime
run is treated just like calcite. When it is caught
early enough, the normal wash process of NMD 80 (4:1) will
be effective enough to remove it. For removing lime
run the same procedure is used as removing calcite.
Use Calcite Presoak (ON CLAY BRICK ONLY) followed by NMD
80. For removing lime run from clay brick use
Calcite Presoak followed by NMD 80. For removing
lime run from concrete masonry units (CMU) use White Scum
Presoak followed by NMD 80.
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White Scum
(calcium silicate) is a result of improper use of a new
masonry cleaner reacting with brick and forming insoluble
salts. This is created by un-buffered acid combining
with silicates and clay. For removing white scum use
White Scum Presoak followed by NMD 80.
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Integral
Water Repellent can sometimes bleed out of the brick
or block, leaving behind a "white haze" that has
a very similar appearance to efflorescence or white scum;
however the removal process is completely different.
For removal use OneRestore
(undiluted).
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Additives -
Admixtures in mortar can bleed out leaving a white
stain that can appear above and below the mortar
joints. It looks similar to calcite and lime
run. For removal use OneRestore followed by NMD 80.
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Sealers
applied incorrectly or failing can look white too.
Knowing the type of sealer is helpful to find the correct
remover. Not knowing the type of sealer, a variety
of products needs to be tested to find the correct
remover.
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Barium
(barium carbonate) attempts to eliminate efflorescence by
reacting with the soluble salts that cause it and locking
it within the brick and hindering migration to the
surface. For removal use OneRestore.
As you can see by
the pictures below, not all white deposits are the same.
While some of them appear to be very similar, a simple test
with water will help you determine if you have efflorescence
or another variety of white deposit. WATER TEST
PROCEDURE:
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Spray water on
an affected area
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If the stain
disappears when wet and re-appears when dry, it might be
efflorescence
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If the stain
is still visible, it may not be efflorescence.
Product
specification sheets must be read for the details on "how
to use". Always test prior to beginning full scale
cleaning operations. Testing should confirm cleaning
effectiveness on each type of surface and stain designated to
be removed. Also test to determine the desired surface
contact time and any potential for adverse reactions with
adjacent materials. Allow test panels to dry thoroughly
before evaluating final appearance and results.
Reference
images below for more information.
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