Deck Nail Versus Deck Screw

For most people planning to build a deck, the choice of deck fastener usually boils down to either deck nails or deck screws (although hidden fasteners are coming on strong).  Here is how these two fasteners compare in terms of design, cost, and long-term effectiveness.

Deck Nail

A deck nail is a corrosion resistant nail used to secure decking boards to a sub structure. This affordable and low-tech fastener has been a standby in the deck construction world long before deck screws came onto the scene. Deck nails are still used more than any other type of fastener for attaching decking.

Hot dipped galvanized nails are the most commonly used nail for deck construction. They offer decent corrosion resistance and are economically priced. Stainless steel nails offer greater rust resistance and less discoloration in woods such as cedar but at a considerably greater cost. There are also aluminum deck nails but these are typically not recommended for deck construction because they're soft, bend easily, and will corrode when they come in contact with the copper preservative used in pressure-treated wood.

For pressure treated wood decking, the nails should be either hot dipped galvanized or stainless steel. For redwood, cedar, and tropical hardwood decking, stainless steel nails are a better choice than galvanized nails because they are much less likely to react with the wood and cause discoloration around the nail head.

As a general rule, at least 1-1/2" of a deck nail should protrude into the joist to which the decking is attached. For 5/4 inch decking use a 10d (3") nail. For thicker decking use a 16d (3-1/2") nail.



Deck Screw

Distinguishing features of a deck screw include corrosion resistance, a sharp tip that allows the screw to be self tapping, a flat countersunk head, and the ability to withstand lateral forces so the screw will bend rather than snap off. A typical deck screw is 2 1/2 to 3 inches long, a length that accommodates conventional 5/4 inch decking.

Deck screws are available with several different coatings. Galvanized screws are the least expensive and least effective in terms of corrosion resistance. Coated deck screws are the most popular and slightly more expensive. These are made by applying a ceramic or enamel coating to an electro-galvanized core. These screws come in different colors, such as brown or green, to better blend in with the color of the decking.

Stainless steel screws offer the best in terms of strength and corrosion resistance, but are also the most expensive. Stainless steel screws are recommended for very moist or humid environments, marine environments, and areas subject to salt spray. They are also recommended for tropical hardwood decking, which can cause staining around the screw head when using coated screws.

Counter-Snap Screw

One of the more unusual deck screws is known as the counter–snap. This innovative screw is slightly longer than a standard deck screw (3 1/2 inches versus 2 1/2 inches) with a head that is designed to be snapped off after the screw is installed. This leaves behind a small hole that becomes virtually invisible after the wood swells around it.

Cost

Deck screws are more expensive than deck nails, an extra expense that most deck owners would agree is worth it in the long run.

Surface Pops

Over time, deck nails are much more likely to pop above the surface of the decking compared to deck screws. However, this tendency can be somewhat mitigated by using spiral or ring shank nails and by sinking the nail heads below the surface of the decking.

Deck screws have greater pop resistance because their threads allow them to more securely grip the substructure. They are also easily removed which is advantageous if it becomes necessary to replace or adjust decking boards.

Pre-drilling

Pre-drilling is generally not required with deck nails when using soft woods such as treated pine or composite lumber. For harder woods such as oak, maple and tropical hardwoods, pre-drilling is recommended at the ends of boards to prevent splitting.

Depending on the hardness of the wood, pre-drilling may or may not be required to install deck screws. For hardwoods such as oak and maple, pre-drilling is a necessity. For softer woods such as pine, pre-drilling is usually not necessary. However, regardless of the type of wood, it is often a good idea to pre-drill screws at the ends of the decking boards to prevent the ends from splitting. Composite decking usually does not require pre-drilling.