Figure 7-24.-Special tile-setting tools.
corrosive conditions often encountered in industrial and
commercial installations. It may be applied over bases
of wood, plywood, concrete, or masonry. This type of
mortar is nonshrinking and nonporous. A bond strength
of over 1,000 pounds per square inch is obtained with
this installation method.
Organic Adhesives
Organic adhesives (mastics) are applied in a thin
layer with a notched trowel. They are solvent-base,
rubber material. Porous materials should be primed
before mastic is applied to prevent some of the
plasticizers and oils from soaking into the backing.
Suitable surfaces include wood, concrete, masonry,
gypsum wallboard, and plaster. The bond strength
available varies considerably among manufacturers, but
the average is about 100 pounds per square inch.
GROUTS
The joints between the tiles must be filled with a
grout selected to meet the tile requirements and
exposure. Tile grouts may be portland cement base,
epoxy base, furans, or latex.
Cement grout consists of portland cement and
admixtures. This is better in terms of waterproofing,
uniform color, whiteness, shrink resistance, and fine
texture than a plain cement. It maybe colored and used
in all areas subject to ordinary use. When the grout is
placed, the tiles should be wet. Moisture is required for
proper curing.
Drywall grout has the same characteristics as
dry-set mortar and is suitable for areas of ordinary use.
Tiles to be set in drywall grout do not require wetting
except during very dry conditions.
Epoxy grout consists of an epoxy resin and
hardener. It produces a joint that is stainproof, resistant
to chemicals, hard, smooth, impermeable, and easy to
clean. It is used extensively in counters that must be kept
sanitary for foods and chemicals. It has the same basic
characteristics as epoxy mortars.
Furan resin grout is used in industrial areas
requiring high resistance to acids and weak alkalies.
Special installation techniques are required with this
type of grouting.
Latex grout is used for a more flexible and less
permeable finish than cement grout. It is made by
introducing a latex additive into the Portland cement
grout mix.
TOOLS
A selection of special tools, shown in figure 7-24,
should be available when doing tile installation work.
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