Deck Screws & Fasteners

Key Takeaways:

• Standard deck screws cost $0.05–$0.15 each — budget $150–$450 for a 300 sq ft deck
• Never use drywall screws or interior nails on a deck — they corrode and fail
• ACQ-compatible screws (stainless or coated) are required for pressure-treated lumber since 2004
• Hidden fastener systems cost 2–3x more but create a clean, screw-free deck surface
• Stainless steel is mandatory for coastal/salt-air environments

Why Deck Fasteners Matter

Deck screws are the most overlooked component of a deck build — and the most common cause of premature failure. The wrong screws in pressure-treated lumber will corrode within 2–3 years, creating rust stains, loose boards, and structural weakness.

Since Canada switched from CCA to ACQ (Alkaline Copper Quaternary) treated lumber in 2004, the copper in the treatment is highly corrosive to standard steel. Every fastener touching ACQ-treated wood must be ACQ-compatible: either stainless steel, hot-dipped galvanized, or polymer-coated.

Types of Deck Fasteners

Face Screws — $0.05–$0.15 each

The standard method. Screws driven through the deck board face into the joist below. Visible screw heads on the surface.

• #8 or #10 gauge, 2.5"–3" length for standard 5/4 deck boards
• Star drive (T25) or square drive (Robertson) — avoid Phillips (strips too easily)
• Self-drilling tip eliminates pre-drilling in softwood
• Budget for a 300 sq ft deck: approximately 700–900 screws = $50–$135

Hidden Fastener Systems — $0.50–$1.50 per clip

No visible screws on the deck surface. Clips or channels grip the board edges and secure to the joist.

System	Price/clip	Method	Best For
Camo Edge	$0.60	Edge-driven screw at 45°	Grooved or square-edge boards
Tiger Claw TC-G	$0.75	Stainless clip between boards	Grooved composite
Trex Hideaway	$0.80	Universal hidden clip	Trex grooved boards
CAMO NEVER-MISS	$1.00	Guide + screw system	Any board type
Fiberon Phantom	$0.85	Clip system	Fiberon grooved boards

Budget for hidden fasteners on a 300 sq ft deck: $350–$600 (vs $50–$135 for face screws).

Structural Fasteners

Beyond deck board attachment, you need structural fasteners for the frame:

• Joist hangers: Simpson Strong-Tie LUS series — $3–$8 each, need 20–30 per deck
• Post-to-beam connectors: $8–$15 each
• Lag screws: 3/8" × 4"–6" for ledger board attachment — $1–$2 each
• Carriage bolts: for railing post attachment — $0.50–$1.50 each

All structural connectors must meet CSA A370 (Connectors for Lumber and Engineered Wood).

Material Selection Guide

Environment	Minimum Fastener	Why
Standard inland	Hot-dipped galvanized	ACQ-compatible, affordable
Coastal/salt air	316 stainless steel	Salt corrodes even galvanized
Ground contact	Hot-dipped galvanized or stainless	Higher moisture exposure
Composite decking	Colour-matched composite screws	Prevents mushrooming, matches colour
Cedar	Stainless steel	Prevents tannin staining around screws

Common Mistakes

• Using electro-galvanized screws — the thin zinc coating fails within 2 years outdoors. Require hot-dipped galvanized (HDG) minimum
• Using screws too short — screw must penetrate joist by minimum 1.5" for proper hold
• Over-driving into composite — creates a dimple that collects water. Use depth-setting clutch
• Skipping pilot holes in hardwood — Ipê and cedar split without pre-drilling
• Mixing metals — stainless screws in galvanized joist hangers creates galvanic corrosion. Match metals

Where to Buy in Canada

Major retailers stocking deck-specific fasteners:

• Home Depot Canada — Grip-Rite, GRK, Simpson Strong-Tie
• Lowe's Canada — Deck Plus, FastenMaster
• Rona — Tree Island (Canadian manufacturer)
• The Ultimate Deck Shop — largest online selection of hidden fastener systems
• Local lumber yards — often carry regional brands and bulk pricing