Installation Guide

35
DECKING
STAIRS
Stairway Detail
» Stair treads built with Trex
®
meet requirements by
the major national building codes. Consult your local
municipality for specific requirements.
» Fasten stair treads continuously across at least four
stringers.
» See chart (at right) for center-to-center spacing of
profiles.
» Dress the sides of the stringers and risers with Trex
fascia or trim for a finished look.
» Most model building codes require the stair treads
to be constructed under the following requirements:
› Stairways must be at least 36" (91.5 cm) wide*
› Stair treads must be at least 11" (28 cm) deep
» Gapping between Trex boards on stair treads must
be 1/4" - 3/8" (0.6 cm - 1 cm).
» The overhang of the stair tread is not to exceed
1/2" (1.3 cm).
* For railings that are installed directly over stair treads, the stair
treads may need to be larger than 36" wide. Refer to local building
code regulations for details prior to installing stairs and railings.
NOTE: Trex rails meet all major building codes for use
as a guardrail system. Local municipalities may require
a graspable handrail on stairways. Check with your local
building code official for local requirements. See Trex
ADA Handrail System on pages 102 - 105.
MAXIMUM SPACING ON CENTER OF JOIST
2" x 6" (5.1 x 15.2 cm), 1" (2.5 cm) Boards 12" (30.5 cm)
Escapes 9" (24 cm)
Riser trim removed
for clarity
12" (30.5 cm) max
for 2" x 6" (5.1 cm x 15.2 cm)
and 1" x 6" (2.5 x 15.2),
9" (24 cm) for Escapes
36" (91.5 cm)
min. width –
4 stringers
required
Stair Tread
1" x 8"
(2.5 cm x 20.3 cm)
Riser
11" (27.9 cm)
min. depth
Stringer
NOTE: 4 stringers are
required if 12" (30.5 cm)
span; 5 stringers are
required if 9" (22.9 cm)
span.
NOTE: For Trex® Select™ Stair Spans refer
to www.trex.com