Coverage will vary with condition of substrate. Required trowel size
will vary with the tile size, type and substrate uniformity. Select the
trowel size that will ensure 100% coverage. Figures below are
presented only as guidelines.
Trowel Size Approximate Coverage
per 50 lbs. (22.68 KG)
1⁄4" x 1⁄4" x 1⁄4" 80-90 sq. ft.
(6 x 6 x 6 mm) (7.4-8.4 m2)
1⁄4" x 3⁄8" x 1⁄4" 55-65 sq. ft.
(6 x 9 x 6 mm) (5.1-6 m2)
When properly prepared, acceptable substrates include:
• Cured concrete, cured mortar beds, brick and masonry (interior
and exterior installations)
• APA Grade Trademarked Exposure 1 Plywood [Underlayment
grade or better, two layers, 11⁄8" (28 mm) total minimum thickness,
16" OC (40 cm), interior floors only].
• Gypsum wallboard (dry interior wall areas only)
• Water resistant gypsum wallboard (e.g.: greenboard, interior walls
only, dry to intermittent water exposure only)
• Cementitious backer units (CBU) or glass mat backer board
• Existing ceramic tile and natural stone, provided existing flooring is
well-bonded to an approved substrate.
• Vinyl composition tile, asphalt tile, linoleum or non-cushioned vinyl
sheet goods, provided such surfaces are single-layered, well-bonded
to an approved substrate and properly prepared.
• Adhesive residue (except tacky or pressure-sensitive adhesive)
d free from oil, grease, dust, paint, sealers
or concrete curing compounds. All contaminants should be removed
prior to installation of tile. Surface protrusions and tile glazes shall be
removed by sanding, scraping or scarifying. After preparation, remove
all dust by vacuuming. Note: Vinyl asbestos tile or any substrate
containing asbestos shall not be sanded, scored or scarified because
of the potential health hazard of breathing dust. Any substrate
containing asbestos must be handled in accordance with existing
EPA regulations. C