|TREX FASCIA INSTALLATION RECOMMENDATIONS
Trex fascia utilized around the perimiter of a deck must be gapped with the same requirements as Trex
Decking to allow for air flow and expansion/contraction of the fascia.
The gapping requirements are as follows:
|END-TO-END/END-TO-WIDTH & ABUTTING GAP
If using 2x8 framing, use 2 screws every 18". If using 2x10 framing use 3 screws every 18". ALWAYS remember
to gap fascia properly.
NOTE: This does not apply if using standard decking boards for fascia. If using decking as fascia use 3 screws
every 12". The top screw should be placed 1" from the top of the rim joist, the second screw in the center of the rim joist,
and the third screw 1" from the bottom of the rim joist. In addition, also use a weather-resistant, construction-grade
adhesive as a SECONDARY fastener when attaching fascia. Remember to wipe away any excess before drying or allowing to drip
on other Trex surfaces.
- 10" rim joists allow for an easier and more aesthetically pleasing installation.
- Miter cuts at butt joints and corners allow for a more aesthetically pleasing installation.
FRAMING AND FASTENING TIPS
Composite decking is a great alternative to traditional wood decking. When building your deck and railing,
it is recommended that code-approved structural material be used as the framing and joists. Trex Decking cannot be used
for structural applications.
DO NOT attach Trex decking directly to any solid surface or watertight system. See
Sleeper Systems. In most cases, install fasteners at a 90° angle
(perpendicular to the board).
|At board ends on the deck's edge, you can install screws placed perpendicularly at the recommended
distance, at a minimum of 1" from the board end and edge, without splitting the board.
|For butt joints, where boards meet over a single joist, add a 2x4 "nailer" board at the butt joint.
This allows you to install a screw at a 90° angle.
Trex decking contains no materials that will harm marine life and is safe for the environment. As long as the dock is
in intermittent contact with water, i.e., splashing and not in continuous direct contact with water, the durability of
Trex decking should not be affected. For docks, a 3/8" width-to-width gap is recommended to allow for increased drainage
due to increased contact with water. In addition, stainless steel fasteners should be used. If there is sufficient contact
with the dock and gasoline, grounding of the dock is also recommended.
ROOFTOP AND SLEEPER DECK SYSTEMS
A sleeper system is a substructure between a solid surface and Trex decking. Drainage, access, and airflow are
critical. Water must be allowed to flow through and away from the deck. For repairs and removal of debris, joist system
access may be necessary.
- It is recommended that building code approved structural material be used as the supports.
- Gapping rules are required when installing Trex decking:
|TYPE OF GAP
|Abutting Solid Objects
- This system should not be allowed to float; it must be attached in a manner that secures the
- The sleeper system must be level and have no uneven undulations. Any uneven areas of the substructure
will transfer to the Trex decking, resulting in uneven decking.
- Trex, when used with a sleeper system, must be supported below its entire length and if using in a
roofing application, the supports must run the direction of the pitch of the roof to facilitate proper
drainage. Sleeper should be placed perpendicular to the deck board orientation.
- For Commercial applications it is recommended to consult local building code official for specific
- If installing decking on an angle, decrease spans 4" for each of the above. (12" for residential and
8" for commercial.)
- For sleeper systems where little debris (pine needles, leaves, sand, dirt) can accumulate either between
or under deck boards, a minimum of 1-1/2" height is allowable and
Trex Universal Hidden Fasteners can be used.
(NOTE: standard decking screws are too long when using 1-1/2" height as this will penetrate
through the sleeper.) For areas with the potential for debris buildup, a minimum of 3-1/2" or greater
height is recommended to allow the debris to be removed along with the use of either Trex Universal Hidden
Fasteners or Deck Screws.
- ALWAYS consult your local building code authority for proper details on roof and railing installation to the
roof structure if required.
- Any deviation from these recommendations could result in voiding of the Trex warranty.
Decking Installation Page 2
Decking Installation Page 3
Trex Transcend Decking