Installation Manual - CertainTeed

CertainTeed WeatherBoards Fiber Cement Siding Installation Manual
Fastening Requirements for
Atypical Walls
Non-vertical Walls
WeatherBoards Fiber Cement can be installed on nonvertical
walls when the walls are no more than 30° off the
vertical, or no less than a 60° angle, measured from the
plane of the ground, and the wall is not a functional roof
above occupied space. The top of the wall cannot be
higher than 30' above grade. Because of different windload
requirements, your local building code may stipulate
a lower height. Use the lesser of the two heights.
1. Install an underlayment of #15 (minimum) felt or
waterproofing membrane.
2. Cap the uppermost edge of the top siding course to
prevent the water from getting behind the siding.
3. Flash all accessories to shed water away from
the substrate.
22
No
less
than
60°
Lap Siding
(up to 8-1/4")
Lap Siding
(9-1/4")
Vertical Siding
1-1/4"
1"
30"
Alternative Wall Systems
WeatherBoards Fiber Cement siding may be applied
over alternative wall systems such as Structural
Insulated Panels (SIP), Insulated Concrete Forms (ICF),
and Rainscreen Systems. Fastening requirements for
the siding depend on the specific wall system design.
Fastening fiber cement onto alternative wall systems
must be in accordance with local building codes.
Refer to the specific wall system manufacturer for
cladding recommendations.
Structural Insulated Panels
Fiber Cement Siding Allowable Wind Load
Structural Insulated Panels (SIP) are a manufactured wall
system, so follow the manufacturer’s instructions for the
application of the SIP and cladding.
The siding attachment methods and their allowable
windload capacities below are based on testing in
accordance with ASTM E330 (wind load) and ASTM
D1037 (fastener withdrawal and pull through). The SIP
system must be capable of supporting the imposed loads
from the siding, including dead load and wind loads.
Fastener Fastening Method Allowable Wind Pressure
1-3/4" roofing nails, double
HD galvanized; 3/8" head
1-3/4" roofing nails, double
HD galvanized; 3/8" head
1-3/4" roofing nails, double
HD galvanized; 3/8" head
6d 2" siding nails; double
HD galvanized
6d 2" siding nails; double
HD galvanized
Blind nailed 8" o.c.
Blind nailed 12" o.c.
Blind nailed 8" o.c.
Face nailed 12" o.c.
6" o.c. around edges; 12" o.c.
each way in the filed
40.44 psf; 125 mph in “B”
exposures up to 30'
27.0 psf, 105 mph in “B”
exposures up to 30'
32.22 psf; 110 mph in “B”
exposures up to 30'
24.4 psf; 100 mph in “B”
exposures up to 30'
18.67 psf; 85 mph in “B”
exposures up to 30'