Pre-Delivery/Install Checklist

TB109
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HOW TO PREVENT GROUT RESIDUE AND TILE STAINING
Technical Bulletin
Technical Services [phone]
custombuildingproducts.com
A Glossary of Terms Used
Grout – mortar or resin-based product used to fill spaces
between tiles
Grout Haze – residue attached to the surface of the tiles
after the grouting process
Grout Retention – grout particles trapped in micro pores,
textures or fissures in the tile surface
Grout Migration – tile discoloration from cement or resins
absorbed into porous tile, primarily edges and unsealed
natural stone
Grout Release – a liquid product applied to the tile
surface that is not absorbed and acts as a temporary
barrier to grout adhesion by filling surface spaces
Sealer – a liquid product applied to the tile that is
absorbed into the tile or stone surface. Some sealers can
be applied in a six-sided method to protect all the tile
surfaces from staining. Unless topical and film-forming,
sealers do not protect against grout retention.
Coating – a liquid sealer or wax applied to the tile
surface before grouting that fills spaces in the surface
and forms a barrier until chemically and mechanically
removed
Additives – liquid added to rinse water to improve grout
cleanup and reduce/eliminate the potential for grout
haze/residues.
Technology is a Factor
Ceramic tile, natural stone and grouts have always been
compatible materials but with the advances in grout
formulation technology using polymers and resins, grout
adhesion has increased dramatically! Though the grout
products are water-cleanable, grout residues must be
removed thoroughly from the tile surfaces before they
set or cure. Adding to the potential for grout haze or
grout retention, the most widely used grouts in today’s
installations are rapid-setting or rapid-curing to achieve
extremely accurate color consistency and to
accommodate fast track installation schedules. These
fast-setting properties can create a challenge for some
grout finishers, especially in warm, dry and windy
conditions.
Technology for tile manufacturing has also advanced
where now porcelain tiles can be profiled to achieve the
strict requirements for slip resistance, to replicate wood
plank and slate textures, or polished so smooth it’s hard
to tell that they’re not natural stones. Some of these
advancements in tile design and manufacturing have
inadvertently created new “spaces” for grout to fill.
All grout formulations combine a binder and an aggregate
or powder to fill joints. The binder might be made of cement
and polymer that attaches to sand, glass or limestone. Other
binders include acrylic resins, urethanes and epoxies.
The grout haze from cement grouts is typically made up of
a combination of the binder and fine particles of the filler.
Resin based grouts - acrylics, urethanes and epoxies most
often leave a clear film residue.
Tile discoloration from grout retention very often leads to
complete tile replacement as the binder and/or fine
aggregate particles become trapped in the tile surface,
becoming permanently “grouted.” More often, unglazed
tiles are the most problematic but polished surfaced tiles
that appear to be smooth can have fissures and “dove-
tailed” pores from the grinding process. When the grout and
tile are similar in color, the residue is unnoticed until traffic
dirt and spills discolor or adhere to the grout, making
remediation much more costly in an occupied project.
Grout migration is usually very evident after the grouting
process as the discoloration darkens the entire tile or picture-
frames the edges. As with grout retention, tiles are typically
permanently damaged.
So, with all these advances, the possibility of a tile
discoloration disaster is always present and only by taking
precautions can you prevent it from happening. The primary
causes for grout haze are listed below. Some instances are
caused by inadequate installation practice, but others will
occur on certain types of tile even when the grout is placed
in a professional manner if protection is not in place.
Primary Causes of Grout Haze
• Spreading too much grout
• Leaving grout too long before finishing
• Improper cleaning technique
• Applying grout to tiles in hot, dry or windy conditions
• Textured/profiled tiles
• Tile with micropores
• Polished tile/stone with fissures
• Porous tiles