Figure 7-22.Tile edges.
Figure 7-23.Trimmer shapes.
fig. 7-22). The lugs assure easy setting and uniform
joints. The edges available vary with the size of the tile
and the manufacturer.
Margins, comers, and base lines are finished with
trimmers of various shapes (fig. 7-23). A complete line
of shaped ceramic trim is available from manufacturers.
Other accessories include towel bars, shelf supports,
paper holders, grab rails, soap holders, tumbler holders,
and combination toothbrush and tumbler holders, to list
a few of the more popular units.
MORTARS AND ADHESIVES
The resistance of ceramic tile to traffic depends
primarily on base and bonding material rigidity, grout
strength, hardness, and the accurate leveling and
smoothness of the individual tiles in the installation. The
four basic installation methods are cement mortar (the
only thick bed method), dry-set mortar, epoxy mortar,
and organic adhesives (mastic).
Cement mortar for setting ceramic tiles is composed
of a mixture of portland cement and sand. The mix
proportions for floors may vary from 1:3 to 1:6 by
volume. For walls, a portland cement, sand, and
hydrated lime mix may vary from 1:3:1 to 1:5 1/2:1.
These proportion ratios are dictated by the project
specifications. The mortar is placed on the surface 3/4
to 1 inch thick on walls and 3/4 inch to 1 1/4 inches thick
on floors. A neat cement bond coat is applied over it
while the cement mortar is fresh and plastic. After
soaking in water for at least 30 minutes, the tiles are
installed over the neat cement bond coat. This type of
installation, with its thick mortar bed, permits wall and
floor surfaces to be sloped. This installation provides a
bond strength of 100 to 200 pounds per square inch. A
waterproof backing is sometimes required, and the
mortar must be damp-cured.
Dry-set mortar is a thin-bed mortar of premixed
portland cement, sand, and admixtures that control the
setting (hardening) time of the mortar. It may be used
over concrete, block, brick, cellular foamed glass,
gypsum wallboard, and unpainted dry cement plaster, as
well as other surfaces. A sealer coat is often required
when the base is gypsum plaster. It is not recommended
for use over wood or wood products. Dry-set mortar can
be applied in one layer 3/32 inch thick, and it provides
a bond strength of 500 pounds per square inch. This
method has excellent water and impact resistance and
may be used on exteriors. The tiles do not have to be
presoaked, but the mortar must be damp-cured.
Epoxy mortar can be applied in a bed as thin as 1/8
inch. When the epoxy resin and hardener are mixed on
the job, the resulting mixture hardens into an extremely
strong, dense setting bed. Pot life, once the parts are
mixed, is about 1 hour if the temperature is 82°F or
higher. This mortar has excellent resistance to the