HardiBacker contains portland cement, ground sand, cellulose fiber, and selected additives. HARDIBACKER ® ceramic tile backerboard contains no asbestos or formaldehyde.
Sheet Size: 3' x 5', 4' x 4', 4' x 8'
Surface dotted for fastener placement
Thickness: 1/4" and 1/2"
Use minimum 5/8" exterior grade plywood or 3/4" exterior grade OSB, complying with Local Building Codes and ANSI A108.11, over joists. Joists' spacing not to exceed a maximum of 16" on center.
Deflection must not exceed L/360 of the span, including live and dead design loads.
Do not use glue between grooves of tongue-and-groove plywood to allow for expansion and contraction of plywood.
HardiBacker must be set into a fresh bed of latex or acrylic modified thinset (complying with ANSI A118.4)(OR) dry-set mortar (use between subfloor and backerboard only) (complying with ANSI A118.1)
Approved fasteners are Minimum 1-1/4" long corrosion-resistant roofing nails (OR) minimum 1-1/4" No. 8 by 0.323" head diameter ribbed counter sinking head, corrosion-resistant screws.
Apply a minimum of 3/32" thick dry-set mortar or modified thinset to subfloor. Embed HARDIBACKER ® sheets firmly and evenly in the wet mortar. Leave 1/8" gap between sheet edges. Using the printed dots as a guide, fasten HARDIBACKER ® sheets with proper nails or screws (as listed in "Materials Required") every 8" over the entire surface. Keep the fasteners between 3/8" and 3/4" from sheet edges and 2" in from sheet corners.Set fastener heads flush with the surface without overdriving.
James Hardie North America (click for more information)