Drywall Screws, Deck Screws and Metal Roofing Screws for Wood

The fastest way to pick a screw is to start with the job, not the bin. A drywall screw, a deck screw and a metal roofing screw look alike in a coffee can, and they fail in different ways when they’re used for the wrong thing. Here’s what WBC carries and what each is for.

Drywall: yellow-zinc coarse-thread screws

For hanging drywall on wood studs, you want coarse-thread drywall screws. The coarse threads bite into wood framing, and the bugle head is shaped to sink just below the surface without tearing the paper face, so you can mud over it.

Drywall screw	Size	Package
Yellow-zinc coarse	#6 x 1 in.	1 lb bucket (about 340)
Yellow Phillips	#6 x 1-1/4 in.	1 lb (about 286) or 5 lb
Yellow Phillips / yellow-zinc coarse	#6 x 1-5/8 in.	1 lb (about 238) or 5 lb bucket (about 1,109)

Which length: 1-1/4 inch is the usual screw for 1/2-inch drywall on wood studs; 1-5/8 inch for 5/8-inch drywall, or for 1/2-inch board over an uneven or older wall. The 1-inch screws are for thin board, 1/4 or 3/8 inch, where they still get enough thread into the stud. Set your screw gun’s depth so the head dimples the paper without breaking it.

Longer yellow bugle-head screws

Screw	Size	Package
Yellow Phillips bugle	#7 x 2 in.	1 lb (about 163)
Yellow-zinc Phillips	#8 x 2-1/2 in.	1 lb (about 125)
Yellow Phillips bugle	#8 x 3 in.	1 lb (about 95) or 5 lb bucket (about 478)

These longer yellow screws get used for all kinds of light indoor wood jobs: shop shelving, jigs, blocking, cleats, temporary bracing. Yellow zinc is an indoor finish, so keep them out of the weather, and don’t use them where a connection carries real load; that takes fasteners rated for it.

Metal roofing and siding on wood: Woodbinder screws

Fastening steel roofing or siding to wood purlins and girts is its own job, and Woodbinder screws are made for it. Each has a T25 star drive, a sealing washer under the head that seals the hole against rain and snowmelt, and a point that starts itself through the metal into the wood.

• Eclipse Woodbinder, brick red, #10 x 1-1/2 in., 100 per bucket. The colored head matches red panels.
• Woodbinder, zinc, #10 x 1-1/2 in., 100 per bucket.

Two things to get right on a Montana pole barn or shop:

• Drive it snug, not crushed. The washer should just compress and seal. Overdriving squashes it out and leaks; underdriving leaves a gap.
• Check what it’s going into. The Eclipse Woodbinder is marked as not suitable for treated lumber; check the zinc version’s label too. Fasten into untreated purlins and girts, or use a screw rated for treated wood.

Decks: softwood deck screws

Softwood deck screws, #10 in 2-5/8 and 3-1/8 inch, 75 to a bucket, are for fastening wood deck boards to joists. Sharp points and deck-screw threads help keep the boards from splitting, and the T25 star drive won’t cam out when you’re driving a few hundred.

• 2-5/8 inch for 5/4 deck boards, which are about 1 inch thick. That leaves plenty in the joist.
• 3-1/8 inch for 2x6 decking, which is 1-1/2 inches thick.

Two screws per board at each joist, three for boards wider than 6 inches, kept 3/4 to 1 inch in from the edge. Start with the drill’s clutch low and turn it up until the heads finish flush; overdriving dents the boards and strips the wood. Deck screws don’t go in joist hangers; those take the connector screws or nails the hanger maker specifies.

Long screws: #10 x 4-inch bronze star-drive

The #10 x 4-inch bronze Torx screws, 1,000 to a box, are for reaching through thick material, like fastening a 2x to the face of a 4x post: the screw passes 1-1/2 inches of 2x and bites 2-1/2 inches into the post. The star drive keeps the bit in the screw on a long drive. Like any general screw, they’re not a substitute for a rated structural fastener.

The Pick

For drywall, the yellow-zinc #6 coarse screws, 1-1/4 inch for 1/2-inch board, 1-5/8 for 5/8-inch. For metal roofing on wood purlins, Woodbinder in red or zinc, into untreated wood. For deck boards, the softwood deck screws, 2-5/8 for 5/4 and 3-1/8 for 2x. For thick material, the 4-inch bronze star-drive screws.

Frequently Asked Questions

What size drywall screw do I need?

1-1/4 inch for 1/2-inch drywall on wood studs, 1-5/8 inch for 5/8-inch drywall.

Can I use drywall screws outside?

No. Yellow zinc is an indoor finish and will rust outdoors. Use deck screws or other exterior-rated screws outside.

What screws go in metal roofing on wood?

Screws made for metal to wood with a sealing washer, like Woodbinder. Drive them until the washer just compresses, and check the label against the wood: the Eclipse Woodbinder is marked not suitable for treated lumber.

How long should deck screws be?

About the board thickness plus 1 to 1-1/2 inches into the joist: 2-5/8 inch for 5/4 boards, 3-1/8 inch for 2x boards.