Best Deck Screws: Coated, Stainless, Composite and Hidden Fasteners
Which fastener suits pressure-treated, cedar and composite boards, the coating your lumber needs, and how many screws to buy for your deck.
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Deck screws fail in two ways: the coating gives up against the copper in modern pressure-treated lumber, or the head snaps or strips when it is driven. The right screw depends on the board (treated pine, cedar or composite), how close you are to salt water, and whether you want visible screw heads at all.
Count first with the deck screw calculator, then pick the fastener type below. This guide compares types by specification; it is not a hands-on product test.
Compared by type
Pros and cons describe each type from its specifications; this is not a hands-on product test. As an Amazon Associate we earn from qualifying purchases.
Coated deck screws (epoxy or ceramic)
Best for: Pressure-treated and cedar boards away from salt water. Check: Listed as approved for ACQ/CA pressure-treated lumber, and a star (Torx) drive.
Pros
Lowest cost per screw
Colours to blend with brown or grey boards
Star drive resists cam-out
Cons
Coating can chip when over-driven
Not for coastal or salt-spray decks
Quality of coatings varies widely
Stainless steel deck screws (305 or 316)
Best for: Coastal decks, cedar and redwood, and anywhere you want no rust streaks. Check: Grade (316 near salt water) and a sharp, Type 17 cutting tip.
Pros
Will not rust or stain tannin-rich woods
Best long-term choice near the sea
No coating to chip
Cons
Costs several times more than coated screws
Softer — heads strip if the bit is worn
Pre-drilling helps in hardwoods
Composite deck screws
Best for: Composite and PVC boards fastened through the face. Check: Board maker's approval and colour-matched heads.
Pros
Reverse threads stop mushrooming of the board surface
Heads colour-matched to the board
Usually keeps the board warranty valid
Cons
Brand- and colour-specific
Visible heads, unlike clip systems
Wrong screw can void a board warranty
Hidden clip fasteners
Best for: Grooved composite boards and a clean, screw-free surface. Check: Matches your board's groove profile and gap width.
Pros
No screw heads on the walking surface
Sets the board gap automatically
Boards can be replaced one at a time on some systems
Cons
Highest cost per square foot
Slower to install
Only works with grooved-edge boards
How many deck screws you need
Face-screwing uses two screws wherever a board crosses a joist, plus about 10% for butt joints, ends and drops. That is the method the deck fastener calculator uses.
Worked example: A 12 x 16 ft deck, 5-1/2 in boards, joists 16 in on centre
Board rows per foot: 12 ÷ (5.5 + 3/16 in gap) = 2.11
Joist crossings per foot: 12 ÷ 16 = 0.75, two screws at each = 3.16 screws per sq ft
192 sq ft × 3.16 × 1.10 = 669 screws (rounded up)
About 669 screws — roughly 8 lb of 2-1/2 in #9 screws (about 90 per lb). At 12 in joist spacing the same deck needs about 892.
Treated lumber and coatings
Modern pressure-treated lumber (ACQ, CA) is more corrosive to steel than the old CCA wood. Use screws the maker lists as approved for it, or stainless.
Within sight of salt water, use 316 stainless; 305 stainless suits most other decks and all cedar and redwood.
Never mix fastener metals at connectors: galvanized joist hangers take galvanized nails or structural screws, stainless hangers take stainless.
Structural connections — ledgers, beams, post bases — need structural screws or bolts rated for the load, not deck screws.
Specs worth reading on the listing
Length: 2-1/2 in for 5/4 boards, 3 in for 2x decking.
Drive: star (Torx) T20/T25 drives far better than Phillips or square.
Tip and threads: a cutting tip and a smooth shank under the head pull the board down tight without splitting.
Box size and count: compare screws per box, not pounds — counts per pound differ by gauge and length.
Safety notes
Wear eye protection when driving screws — chipped coatings and wood splinters fly.
Use structural screws or bolts, not deck screws, for the ledger, beams and post connections, and follow your local deck code.
Keep the impact driver's clutch or speed low near board ends to avoid splitting and stripped heads.
Frequently asked questions
What are the best deck screws for pressure-treated wood?
Coated deck screws that the maker lists as approved for ACQ or CA pressure-treated lumber, or 305/316 stainless steel. Plain zinc-plated or drywall screws corrode quickly in modern treated wood.
How many deck screws do I need per square foot?
About 3.5 per sq ft with 5-1/2 in boards and joists 16 in on centre, including 10% extra; about 4.6 at 12 in spacing. A 12 x 16 ft deck takes roughly 670 screws.
Are stainless steel deck screws worth it?
Near salt water, and on cedar or redwood, yes: they will not rust or leave black stains. Elsewhere, good coated screws approved for treated lumber are a sound, cheaper choice.
Screws or hidden fasteners for composite decking?
Either works if the board maker approves it. Hidden clips give a screw-free surface but need grooved boards and cost more; colour-matched composite screws are faster and work on solid-edge boards.
What length deck screw should I use?
2-1/2 in for 5/4 (1 in actual) boards and 3 in for 2x (1-1/2 in actual) decking, so at least 1-1/2 in of thread goes into the joist.