How deck boards land on the frame

The starter board — closest to the house, butted square to the ledger. Pin it with a single screw at one end, check with a 3-4-5 corner triangle (or measure diagonal corner-to-corner of the deck), adjust until square, then drive permanent fasteners. The rest of the field boards reference off this starter. If the starter is off-square by even 1/8″, the error compounds across the deck.

3/16″ (about 5 mm) is the IRC R507.6 standard for thermal expansion + drainage. Wet PT and cedar boards already have moisture inside that will shrink by ~1/8″ over the first year, so wet boards can go down butted tight or 1/16″ apart and end up at ~3/16″ after dry-down. Composite is dimensionally stable — install at 3/16″ from day one. Wider gap (1/4″ or 5/16″) is acceptable in heavy-rain climates for faster drainage.

Face screws: faster install, lower hardware cost (~$0.85/sqft for screws + plugs vs $1.65/sqft for clips), required for PT and cedar (no groove for clips). Trade-off: screw heads visible, plugs can pop loose over time. Hidden clips: clean look, no visible fasteners, required by some composite warranties (Trex Transcend, TimberTech AZEK). Trade-off: 25-40% more install labor, clip system locked to one brand. Most premium decks use clips; budget builds use screws.

Yes if you're using face screws on capped composite. The cap layer can be cosmetically damaged by aggressive screw heads, and the plug system hides the screw + protects against water ingress at the head. Plugs add ~$0.30/sqft and 8-12% install time. Some composite manufacturers (Trex Enhance) offer composite plug kits color-matched to their products. PT and cedar don't need plugs — the wood absorbs minor screw-head bruising naturally.

A perimeter band of contrasting decking that wraps the deck edge — hides board ends, creates visual framing, signals premium finish. Cost premium is typically $4-7/lf for the border board itself plus 6-10% extra labor for the perimeter blocking and miter cuts. On a 16×20 deck (72 lf perimeter), expect $400-700 added on top of straight-board cost. Returns 2-4% resale value lift in mid-to-upper markets.

PT and cedar — yes, but expect boards to shrink as they dry. Install slightly butted (1/16″ apart) so the post-shrink gap lands at ~3/16″. Composite — only above 40°F per manufacturer install guides; thermal expansion math assumes installation temperature so a winter install needs slightly wider gaps (1/4″ at install) to end up at correct gap at average use temperature. Adhesives + sealants won't cure below 35°F regardless of material.