Why Flat Head Screws?

To provide a smooth surface for the most comfortable walking conditions and the best appearance, flat head screws are a must. They are countersunk into the deck board to provide that flush surface that’s so desired. Whether your deck is built from cedar, treated lumber or composite products, a flat head will create the finish you want.

Typically a deck screw is 2 1/2″ and that length is measured from the top of the head (which would be flush with the surface) to the tip of the screw. This is plenty long enough to secure the 1 to 2” deck boards that people are using today. Flat screws are generally available in Phillips, square or torx heads as well, so you can take your pick and grab a bit to get started on the installation.

Are They Necessary On the Framing?

Although round head wood screws are available, most people do not use them anywhere on a deck. You might use oval countersunk screws on the framing, railing and stairs although they do leave a slight mound. Only flat head countersunk screws are used on the deck board.

Other fasteners used in the framing include lag bolts and carriage bolts – both with the typical bolt heads (either round or hex). Because the framing is hidden for the most part the head of your fasteners is not as important, although for consistency and convenience the same type of driving method is often used. Whether you prefer a square or a torx head, keeping your bit in the power driver is much quicker than switching it out for each fastener.

In order to provide the smoothest, most attractive finish on your decking flat head screws are the only choice. Order them in stainless steel to provide a lifelong strength and resistant to corrosion as well. Then sit back and enjoy your beautiful outdoor living space.

Nails, screws, bolts and lags – decks run the gamut of different fasteners. Each area is held together with a certain type.

Footings and Framing

Depending on how the foundation of your deck is installed, there may be post saddles or pins used on the footings. In other situations a wooden post is bolted into a floating pier or post spike.

Bolts and lags are used in the framing. Often the ledger board is bolted into the house and the beams are lagged into those wooden posts. Different contractors use different deck fasteners depending on their personal preferences and the applicable building codes.

Deck Boards

Most often deck boards are attached using deck screws. This provides a better finish on the decking and with the right tools, is installed just as quickly as nails are.

Deck screws offer a better finish when they are epoxy or ceramic coated. This type of fastener allows for color matching and a smoother, better looking finish. If nails are used the surface will be marred by silver/grey marks and it will be much more difficult to remove damaged deck boards. These coatings also offer better corrosion resistance.

Railing and Stairs

Nails can be used in the stairs and on railing components, although this is still a common place for screws. Since deck boards are often used for the stairs, the same deck screws that were used on the deck surface are seen. Nails often fasten the stringers to the framing.

Railing pickets are screwed in, although much shorter screws are used. When tempered glass is used the framings may be nailed, but with aluminum pickets and component products, everything is fit together with screws.

All deck fasteners need to be corrosion resistant, whether that is through a plating or coating or due to the material itself. Stainless steel fasteners are ideal for outdoor projects like a deck and well worth the extra expense. For a dependable, long lasting finish choose deck fasteners with the highest levels of strength.

Stats for the Typical Deck Screw

Most often a deck screw will be 2 1/2″ long and either a #7, #8 or #10 in size. Every so often you’ll find the need for a #12 screw. And thinner deck board will require 1 5/8” lengths.

Screws for use on decks, fences and other outdoor structures are most often driven with a square (or Robertson) head, a Phillips head or a Torx head. Each of these has advantages over the other with regards to commonly used tools, less wear or stripping and speed of installation.

Materials and Coatings for Decking Screws

The material you choose for your deck screws needs to be compatible with the material of your deck board. For instance, composite decking needs to be installed using composite deck screws – a good choice both for strength and looks. Wood decking, on the other hand, is best installed using stainless steel composite or hardware that has been tested for use with ACQ, the common chemical treatment for softwood lumber.

Composite deck screws can also be stainless steel, but are available in colors designed to compliment and match the colored deck boards, trim and railing components. Ceramic coated screws can be used with both pressure treated lumber and composite decking. A more widely seen option is epoxy coated deck screws. These are available in a wide variety of colors and the resin coating will not chip off as easily during installation (as can be the case with ceramic).

When building with ACQ treated lumber, always be sure that the fastener material is compatible with that chemical concoction. Check with the fastener manufacturer or read through the MSDS for ACQ or the screws themselves to find out which materials to avoid and which are safe.

Unless you opt for an invisible fastener system, the surface of your deck will be dotted with screws. Be sure to take the time and choose the best possible deck screws for your application. The final product will be worth it.