When installed with regular screws, PVC and wood-plastic composites can expand and bow because the screws don’t allow the material to move as temperatures rise and fall. I recently installed 130 ft. of TimberTech fascia and riser boards using Starborn Industries’ DeckFast Fascia System. The specialty drill bit and matching screws allow natural expansion, which prevents the composite fascia boards from bowing.

In one operation, the Fascia Tool drill bit bores a clearance hole and provides a countersink that matches the company’s 1-7/8-in.-long Fascia Screws. The depth stop’s O-ring bumper prevents marring the fascia when drilling. The oversize hole left by the bit allows the fascia boards to expand and contract without over-stressing the screw shanks. Once they’re installed, the 3/8-in.-dia. screw heads are visible but flush with the surface of the fascia board. To keep the screws looking uniform, I positioned pairs of them at equal distances from the top and bottom edges of the trim and spaced them every 16 in. It’s important not to over-tighten the screws, which would restrict board movement.

Fascia screws are available in stainless steel and epoxy-coated steel in 11 colors to match the most common colors of manufactured deck-fascia boards. My local lumber dealers don’t stock the DeckFast Fascia System, so I ordered the parts online. Manasquan Fasteners and DecksDirect carry the tool ($15) and the screws, which are sold in 100-count packs (epoxy-coated steel, $11; stainless steel, $19). The screws and special drill bit are easy to use, and the system seems like a promising way to fasten fascia boards made from PVC or wood-plastic composites with less risk of the material buckling later on.