Decking Screws vs Hidden Fasteners: A Buyer's Guide

The fastener you use on a deck is one of the most important decisions you will make — the wrong screw can corrode in a season, stain the decking or allow boards to pop up. Here is what to know before you buy.

Corrosion resistance is non-negotiable

All deck fasteners must be corrosion-resistant. The copper preservative in ACQ and CA pressure-treated lumber is chemically aggressive and will corrode plain steel screws within a year or two. The IRC requires that fasteners in contact with preservative-treated wood be either hot-dip galvanized, stainless steel, or specifically listed by the screw manufacturer as compatible with the preservative treatment used.

Deck screws vs structural screws

Deck screws (coarse thread, bugle head, typically #8 or #10 x 2.5") are the standard fastener for attaching decking to joists. They hold adequately for the surface but are not engineered for structural connections. Structural screws (LedgerLOK, Titen HD, etc.) are different products with ICC approvals for specific structural load cases — ledger attachments, post bases and joist hangers.

Composite decking requires composite screws

Composite decking boards are denser and harder than wood. Standard wood deck screws can strip out or cause the composite material to spider-crack around the head. Use screws rated for composite decking — they have reverse-thread sections and modified head geometry that prevent mushrooming. Many composite manufacturers void the product warranty if you use non-approved fasteners.

Hidden fastener systems

Hidden fasteners clip into the groove on the edge of grooved composite or PVC decking boards and secure the board to the joist without any face screws visible. They produce a cleaner look and allow boards to expand and contract laterally without buckling. The downside: they are slower to install, cost more, and require grooved-edge boards. They also make it harder to replace a single damaged board later.

• For grooved composite or PVC: use hidden fasteners (e.g. Camo, Tiger Claw, EB-TY).
• For solid-edge composite: use composite-approved face screws, pre-drilling end boards.
• For pressure-treated or cedar: use hot-dip galvanized or stainless #8 or #10 deck screws.
• Always pre-drill the last 8 inches of any board near a cut end to prevent splitting.