Full Product Manual

Construction Guide | 21
Exterior Installation of
PermaBASE
®
Cement Board
General: All framing should comply with local building code
requirements and be designed to provide support with a
maximum allowable deection of L/360 under all intended live
(including wind) and dead loads.
Note: Cut or score PermaBASE on rough side of panel.
Control Joints: For exterior installations, consult nish
manufacturer’s instructions for spacing requirements. For
exterior tile applications, control joints should be spaced a
maximum of every 12'. If no recommendation is available, allow a
maximum of 16 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 specications of architect. Control joint cavity shall not be
lled with coating or other materials.
WALLS AND CEILINGS
Wall Framing: Studs should be spaced a maximum of 16"
o.c. Edges/ends of PermaBASE parallel to framing should be
continuously supported. Provide additional blocking when
necessary to permit proper PermaBASE attachment. Do not
install PermaBASE directly over protrusions from stud plane such
as heavy brackets or fastener heads.
Ceiling Framing: The deection of the complete ceiling assembly
due to dead load (including insulation, PermaBASE, bonding
material and facing material) should not exceed L/360. The
dead load applied to the ceiling frame should not exceed 10
psf. Ceiling joist or furring channel should not exceed 16" o.c.
(Edges of PermaBASE parallel to framing should be continuously
supported.) Provide additional blocking when necessary to permit
proper PermaBASE attachment.
Water Barrier: While PermaBASE is unaected by moisture, a
water/air resistive barrier (WRB) must be installed to protect
the cavity. The type and specic placement or location of the
water barrier will vary based on local building codes and/or
manufacturers' warranties. Consult the WRB manufacturer’s
recommendations for specic installation guidelines.
PermaBASE Cement Board: Apply PermaBASE with ends and
edges closely butted but not forced together. Stagger end joints
in successive courses. Drive fasteners into eld of cement board
rst, working toward ends and edges. Space fasteners maximum
8" o.c. for walls, 6" o.c. for ceilings with perimeter fasteners at
least 3/8" and less than 5/8" from ends and edges.
Joint Reinforcement: Trowel bonding material to completely
ll the tapered recessed board joints and gaps between each
panel. On non-tapered joints, apply a 6" wide, approximately 1/16"
thick coat of bonding material over entire joint. For all joints,
immediately embed 4" alkali-resistant berglass mesh tape fully
into applied bonding material and allow to cure. Same bonding
material should be applied to corners, control joints, trims or
other accessories. Feather bonding material over fasteners to
fully conceal.
DECKS
Suboor: Plywood should be securely glued and fastened to oor
joists spaced a maximum of 16"o.c. Suboor should be sloped at
a minimum pitch of 1/4" per foot. The oor surface should be true
to plane within 1/8" in 10'.
Underlayment: Using a 1/4" square-notched trowel, apply
a setting bed of dry-set mortar to the suboor. Immediately
laminate PermaBASE to suboor, leaving a 1/8" space between
boards at all joints and corners. Leave a 1/4" gap along walls.
Stagger joints so they do not line up with underlying substrate
joints. Fasten PermaBASE 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 the
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,
embed alkali-resistant 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 it to cure.
Waterproof Membrane: Trowel apply waterproof membrane
to the entire surface of the cement board, following membrane
manufacturer’s installation instructions in detail.