After framing, decking, and installing the railing, it is time to trim the deck, beginning with covering the rim joist with deck fascia. This video from Trex completely describes the process of installing deck fascia.
Before you begin any project, wear the appropriate personal safety equipment. Eye protection, ear protection, gloves, long pants, a long-sleeved shirt, and reinforced-toe shoes are recommended. Always make sure that you have a first aid kit nearby. For any home project, follow the local code and permitting requirements.
Spacer installation will allow the fascia material to be installed flush with the top of the decking, allow airflow between the fascia material and the rim joist of the deck frame, and prevent debris and water from collecting between the fascia and the rim of the deck.
Step 1: Place Fascia Spacers
To install Trex® Fascia flush to the top of the decking, use spacers attached to the frame and placed at the correct intervals for fastener attachment. The spacer material should be rot-resistant, approximately 3/16 inch to 1/4 inch thick, a minimum of 1 inch wide, and cut to the length of the deck's rim joist. In this project, the spacer was 3/16 inch thick, 1 inch wide, and 7 1/4 inches long. The spacer material can be purchased in long lengths, cut to shorter lengths, or made on-site from a rot-resistant material such as treated lumber.
Step 2: Install Spacers
Install the spacers at 9 inches on center. The maximum spacing between the fascia fasteners is 18 inches.
Step 3: Drill Hole in Spacers
Using a 3/16 inch wood pre-drill bit, drill one hole in the middle of the spacer. Place a single fastener in the pre-drilled hole of the spacer and tighten until the fastener indents into the spacer. Do not overtighten, as it could split the spacer.
Step 4: Determine Fastener Placement
Measure and mark every 18 inches on the fascia to determine where to place the fasteners. Mark 2 inches down from the top of the fascia for the top fastener. To determine the placement and how many fasteners are needed, see the diagram below or visit our fastener placement guidelines.
Step 5: Decide on the Fastener Color or Plug
The fascia fasteners can be color-matched or come with a color-matched plug that will hide the fastener once complete. The color-matched fastener will be indented to be flush with the fascia material. The hidden fastener with plug option is indented deeper to allow room for the plug. Fascia screws will require a specific bit that drills a specified hole and recesses the fastener to be flush or indented into the fascia material, depending on whether the fascia screw will have a plug on top or not. This drill bit will be purchased separately from the fastener company.
Step 6: Pre-Drill Fastener Holes
Place the fascia on a table or sawhorses and pre-drill the holes for the fasteners. Clamp a small piece of 2x4 to the guardrail post on top of the decking. The 2x4 should overhang the edge of the deck by at least 1 inch. Clamp multiple 2x4s so the fascia has a stopping point along the top of the deck.
Step 7: Clamp the Fascia
Place the fascia against the rim joist and tight against the 2x4 blocks clamped on the decking. Clamp the fascia to the 2x4 blocks. Make sure that the fascia is tight against the rim of the deck. This will keep the fascia flush with the top of the decking. The clamp will allow working hands-free while fastening the fascia.
Step 8: Drill in the Fasteners
Pre-drill the fascia hole with a 1/8-inch wood drill bit. Only drill through the depth of the spacer, not into the deck's rim joist. Then, drill the fasteners through the fascia and into the rim joist.
Step 9: Ensure the Fascia is Flush With the Deck
Using a scrap 2x4 or a speed square, hold the 2x4 on top of the decking and fascia. Make sure that the fascia is flush with the top of the decking. The fascia can be raised or lowered if needed as the fasteners are installed. This will ensure that the fascia is flush with the top of the decking the entire length of the deck.
Step 10: Plug Holes
Once all the fasteners have been installed, if applicable, tap the composite deck plugs into the holes on top of the screws.
