Technical Specifications

15
SEALANT JOINTS/CAULKING
Fasten Single Flange Sealant Backers at inside
corners (one wall at corner), along window
and door jambs, and transition points with
other cladding. Fasten to framing, blocking or
plywood/OSB sheathing at 12-14” o.c. with
the 3/8” bump/sealant portion butting the
corner or jamb.
Sealant complying with ASTM C-920 is
required where Single and/or Double Flange
Sealant Backer is used.
Refer to the sealant manufacturer’s
instructions or requirements.
Place low-adhesive tape (masking or painter’s)
over the panel along the areas requiring
sealant joints for a clean caulk line.
Fill the gap between the panels with a color-
matched/coordinating sealant which complies
with the ASTM C-920 standard. Nichiha
Sealant Backers allow for the proper depth of
sealant (75-80%).
Before removing tape, press the surface of the
sealant with a caulk spatula or similar tool to
ensure an even surface. Remove masking tape
before sealant cures. If excess sealant adheres
to panel, remove completely using a putty
knife or soft cloth.
Fig. 30