Installation of PermaBASE™ Foam Tile Backer
General: All framing should comply with local building code requirements and be designed to provide support with a maximum allowable deflection of L/360 under all intended loads. Wall framing members shall be spaced a maximum of 16" o.c. and shall be a minimum of 2"x 4" nominal (wood) or 20 gauge (metal). Install tile and tile setting materials in accordance with current ANSI specifications and Tile Council of North America (TCNA) guidelines.
Control Joints: Consult TCNA Handbook Installation Method EJ171. Architect, builder, or design professional must specify the location of all control joints. For interior installations, allow a maximum of 30 lineal feet between control joints. A control joint must be installed but not limited to the following locations: where expansion joints occur in the framing or building (discontinue all cross-furring members located behind joint); when boards abut dissimilar materials; where framing material changes; at changes of building shape or structural system; at each story separation. Place control joints at corners of window and door openings or follow specifications of the architect. Control joint cavity shall not be filled with coating or other materials.
Wall Framing: Edges of PermaBASE™ Foam Tile Backer parallel to framing should be continuously supported. Provide additional blocking when necessary to permit proper Tile Backer attachment. Do not install PermaBASE Foam Tile Backer directly over protrusions from stud plane, such as heavy brackets and fastener heads. Studs above a shower floor should either be notched or furred to accommodate the thickness of the waterproof membrane or pan. The surround opening for a tub or precast shower receptor should not be more than 1/4" longer than the unit to be installed.
Installation: Cut PermaBASE™ Foam Tile Backer using a utility knife to score/cut through the entire board. Apply PermaBASE with ends and edges closely butted but not forced together. Stagger ends joints in successive courses. Drive fasteners into the field of board first, working toward ends and edges. Space fasteners maximum 8"o.c. for walls, with perimeter fasteners at least 1/2" and less than 3/4" from ends and edges. Ensure Foam Tile Backer is tight to framing. Install screws flush with surface, do not overdrive screws.
Joint Reinforcement: Trowel bonding material to completely fill the board joints and gaps between each panel. Apply a 6" wide, approx. 1/16" thick coat of bonding material over the entire joint. For all joints, immediately embed 2" alkali-resistant fiberglass mesh tape fully into applied bonding material and allow it to cure. For outside corners, 4" wide alkali-resistant mesh tape is recommended. The same bonding material should be applied to corners, control joints, trims, and other accessories. Feather bonding material over fasteners to fully conceal. Bonding material to be modified dry-set mortar compliant with ANSI A118.4 standards. In wet-area installations, apply approved fluid applied waterproofing per manufacturer’s recommendations over joints and fastener heads.
Alternate Sealant/Waterproofing Application: Apply continuous bead of approved sealant to the bottom edge of PermaBASE™ Foam Tile Backer. Install board and ensure that when it is butted at the base, the sealant squeezes out. There must be at least 1/8" gap between PermaBASE™ Foam Tile Backer and base that is completely filled with sealant. Sealant must extend onto PermaBASE™ Foam Tile Backer surface a minimum of 1" beyond joint on either side. Fasten PermaBASE Foam Tile Backer to the studs with approved cement board fasteners flush to the surface of the board at a maximum spacing of 6" and within 1/2"–1" of the perimeter edges. Apply a continuous bead of sealant to the top edge so that when
PermaBASE™ Foam Tile Backer is butted the sealant squeezes out. Ensure a tight seal at the joint. Fasten Tile Backer to the studs and spread any excess sealant with a putty knife across both sides of the joint. Sealant must cover joints to at least 1" beyond either side of the joint. Once all boards have been installed following this procedure, seal all fasteners with approximately a 2" diameter coating of sealant. Seal all corner joints. All joints should be completely filled with sealant and sealant spread minimum 1" beyond either side of the joint.