EFFLORESCENCE
ldentifying, Preventing & Controlling
What is Efflorescence?
Efflorescence is a crystalline deposit that appears on the
surface of grout joints or tile as a whitish powder or crust and is generally
harmless except for appearance.
A combination of circumstances causes efflorescence. First, there must be
minerals (soluble salts) present in the substrate. All setting materials,
including grout and thin set mixtures, used in the installation of tiles contain
minerals. Minerals can also be found in the tiles. the foundation and the
ground. Second, water must be present to act as a vehicle for the minerals to
pass through to the surface. Third, either evaporation, hydrostatic pressure or
similar force must cause the water and minerals to migrate to the surface. All
three conditions must be present to produce efflorescence. Eliminate any one
element and the problem will not appear, unless there is external water
and minerals present. As time passes the amount of efflorescence diminishes as
the original amount of minerals that were present is gradually eliminated. Also,
dark grout joints exhibit more efflorescence than light coloured grout. The
phenomenon of efflorescence is illustrated in Figures I, II & III
How to Prevent Efflorescence
Prevent efflorescence by eliminating one of the three contributing factors.
Remove the minerals in the setting materials by using only washed sand or using
proprietary grout mixtures. Eliminate unnecessary water by controlling
job
conditions and avoiding setting tiles when rain is pending. Grouting quarry
tiles at temperatures less than 50oF invites trouble. Using a vapor
barrier between the foundation and the ground will also help reduce the passage
of water in the ground through the substrate. Seal the tile surfaces with
Everblock or Everseal Extra. These products allow the treated
surface to breath, allowing moisture trapped beneath the treated surface to
safely pass through (98%) while remaining water repellent and greatly reducing,
if not eliminating, the amount of minerals that pass through the surface. See
Figure IV.
How to Correct Efflorescence
Some efflorescence can be removed by using a stiff bristle brush, either dry,
or with clean water, followed by clean water rinsing. Chemical removal, such as
acid
rinsing, is somewhat drastic and controversial. However, in severe case this is
the only alternative. Use Evergrout or Everacid.
NOTE:
The following information is assembled in part by articles published by MMSA Materials & Methods Standards Assoc. BDI SOLUTIONS expresses no warranty, either expressed or implied, as to the accurateness of these recommendations.
As with any chemical compound, read and understand the Material Safety Data Sheet (MSDS) before initial use.
General lnformation: info@bdisolutions.com
