Hide Structural Screws Behind Wood Plugs
The Problem
Structural screws are the right fastener for a deck's rim joist — but their big washer heads are built for holding power, not looks. On a rim or fascia board at eye level, a row of exposed hardware reads as unfinished, and that's exactly the part of the deck everyone sees.
The Technique
- At each fastener location, drill a counterbore first — a flat-bottomed hole wide enough for the screw head and sized to match a wood plug.
- Drive the structural screw inside the counterbore, seating the head below the surface.
- Glue a wood plug into the counterbore over the head and tap it home. Outdoors, use an exterior-rated glue.
- Trim the plug flush with a flush-cut saw and sand it smooth.
The screw does its structural job; the surface shows a wood dot instead of a washer head.
Pro tip: Cut your plugs from offcuts of the same decking or rim material with a plug cutter, and orient each plug's grain with the board when you glue it in. A store-bought plug in the wrong species announces itself almost as loudly as the screw head did.
Safety note: A counterbore moves the screw head deeper into the board, which costs you thread length in the member behind it. Check the screw manufacturer's specs for required penetration and step up to a longer screw to make up the counterbore depth — a structural screw that's lost its embedment isn't structural anymore.