Full Product Manual

18 | PermaBASE Building Products
FLOORS AND COUNTERS
Suboor or Base: For ooring applications with 16” o.c. oor
joists, 5/8” tongue-and-groove exterior-grade plywood or 3/4”
tongue-and-groove exterior-grade OSB may be used. For 19.2”
o.c. and 24” o.c. oor joists, 3/4” tongue-and-groove exterior-
grade plywood or OSB must be used. Tile size for oors with 24”
o.c. oor joists must be 12” x 12” or larger. The joist and suboor
assembly must meet L/360 as well as the appropriate code
tables for live and dead loads.
Underlayment: Using a 1/4” square-notched trowel, apply a
setting bed of polymer-modied mortar (or thin-set mortar) to
the suboor or counter base. Immediately laminate PermaBASE®
Cement Board to suboor or base with ends and edges closely
butted but not forced together. Leave a 1/4” gap along walls.
Stagger all joints so that they do not line up with underlying
substrate joints. Fasten PermaBASE Cement Board every 8” o.c.
throughout board eld and around all edges while setting bed
mortar is still workable. Around perimeter of each board, locate
fasteners 2” from corners and not less than 3/8” from the edges.
Fill all joints solid with bonding material. On non-tapered joints
such as butt ends, apply a 6” wide, 1/16” thick coat over the entire
joint. For all joints, immediately embed 2” berglass mesh tape
fully into applied bonding material; ensure that tape is centered
over joint. Apply bonding material over fasteners to fully conceal.
Remove all excess bonding material and allow to cure.
LIMITATIONS
• Joints should be treated with alkali-resistant fiberglass mesh
tape set in a polymer-modified mortar.
• Conventional paper drywall tape, joint compound and drywall
nails or screws should not be used.
• Maximum wall framing spacing should not exceed 16” o.c. and
must be designed to limit deflection to L/360 under all live and
dead loads.
• Steel framing must be 20 gauge (galvanized) or heavier – 16” o.c.
• 1/4” UltraBacker should not be used on walls or ceilings.
• PermaBASE Cement Board is not a water barrier; consult local
building code for moisture barrier requirements.
• Not recommended for use under vinyl flooring.
• PermaBASE Cement Board should not be exposed to
temperatures over 220°F (105°C).
• PermaBASE Cement Board is not a nailing base for other
finishes.
COUNTERTOP INSTALLATION
1. OSB/Plywood
2. Dry-Set Mortar
3. PermaBASE Cement Board
4. Fiberglass Mesh Tape (Alkali-
Resistant) Embedded in Mortar
5. Dry-Set Mortar
6. Tile
FLOOR UNDERLAYMENT
1. Joists
2. Subfloor
3. Dry-Set
Mortar
4. PermaBASE
Cement Board
5. Fiberglass Mesh Tape
(Alkali Resistant)
6. Dry-Set Mortar
7. Tile
FLOOR UNDERLAYMENT
1. Open-Web
Wood Trusses
2. Subfloor
3. Dry-Set Mortar
4. PermaBASE
Cement Board
5. Mesh Tape
6. Dry-Set Mortar
7. Mortar Bed
8. Tile
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