Concrete masonry units manufactured with an integral water-repellent,
will reduce, if not eliminate, efflorescence. The water-repellent
units can be used as the finished product for a weather tight building.
Water penetration problems and efflorescence are more likely to
occur in masonry units left unprotected or incorrectly installed.
Efflorescence, a deposit of soluble salts (usually white) sometimes
appears on the masonry surface. Efflorescence is most obvious in
the winter but may be observed throughout the year following heavy
rains and drops in temperature.
A combination of circumstances caused efflorescence. Unless corrected,
efflorescence may result in the disintegration of masonry. Soluble
salts inherent in cements, mortar and aggregate react with chemicals
in the atmosphere. Moisture trapped or present inside a masonry
wall will, through evaporation or hydrostatic pressure, move to
the outside surface.
Removing Efflorescence...
The removal of most types of efflorescence is relatively easy,
as most efflorescing salts are water soluble and many will disappear
with normal weather. Before removing efflorescence, determine the
source of the problem and take steps to correct it. Doing so will
help prevent water penetration and further efflorescence. In general,
most efflorescence can be removed by dry-brushing followed by flushing
with clean water. If this is not satisfactory, wash the surface
with a dilute solution of acid (5 to 10 percent). For integrally
colored masonry, a more dilute solution (2 percent) may be necessary
to prevent surface etching that might change colors and texture.
Contact your masonry representative or qualified technical specialist
when a questions arises regarding the removal of efflorescence.
|
