5 Types of Deck Fasteners

In the construction of your deck the nails, screws, bolts and other kinds of deck fasteners are the glue that will hold your project together making it strong and stable for years to come. Some of these choices such as the size of lag screws or carriage bolts are regulated by local building codes for strength and safety issues. Others choices such as whether to use nails or screws depend more upon personal homeowner preferences than local building codes.

No matter what type of fastener that you select there is a rule of thumb for determining which length you require: the penetration of the fastener into the lower piece of material should be equal to or greater than the thickness of the upper piece of material. An example would be a 3 inch or 3.5 inch fastener used to install a 1.5 inch board to another.

In selecting fasteners, pay close attention to their corrosion resistnce as well as their holding capacity. Nails, screws, etc. that corrode prematurely or are not strong enough for the task can actually weaken a deck. Sometimes do-it-yourselfers make the mistake of skimping on fasteners in terms of all-round quality and durability for the job and end up regretting their error, especially when they are forced to complete a deck repair far too early.

The most common and usually fastest way of fastening wood together is with nails. If the right kind of nail is chosen and installed correctly the joint will remain tight for many long years. Nails that have smooth shanks have the least holding power. When the wood shrinks over time, the nails will loosen and the lumber joints will separate. Spiral groove or ring shank nails have much more holding power. In addition the thicker a nail is, the more wood surface it touches and the more wood the nail's shank displaces, the better it will hold.

Generally deck construction requires the use of hot-dipped galvanized nails that are designed to resist corrosion. Stainless steel and aluminum nails resist rust more effectively but have less holding power that galvanized nails. Stainless steel nails are expensive but are ideal in wet situations while aluminum nails are soft and easily bent.

Screws can be a better choice than nails for several reasons. They provide more holding power than nails and are able to force a bowed board flat more easily. The use of screws will also eliminate the indentations often produced in the wood from hammering. Screws can also be removed without damaging the wood so that the board does not have to be discarded. Deck screws have a bugle shaped head and aggressive threads. Square drive bit screws are a better choice because they are easier to drive and the drive bits last longer than standard Philips drive bits. Galvanized screws work well on pressure treated lumber while stainless steel is a better choice with redwood, western red cedar and tropical hardwoords. Composite decking can usually be installed with galvanized fasteners.

Bolts are heavy duty fasteners intended to carry bigger loads than nails and screws. Carriage bolts and lag screws are used to connect ledger boards, railing posts and other critical frame members. Lag screws, which are sometimes called lag bolts, are thick screws with coarse threads and heads that require the use of a socket wrench in the fastening process. Always use a washer so that the head of the lag screw will not sink into the lumber and thus reduce holding power. Lag screws are used in places where extra strength is needed but only one side of the connection can be reached. Carriage bolts, which require the use of a washer and nut, are usually stronger than lag screws. They require pilot holes to be drilled through the wood prior to hammering them into place and adding the washer and nut to the threaded end.

Hidden deck fasteners are a relatively new product available in recent years. There are several options including deck clips and continuous deck fasteners. These items allow the installation of decking boards to be done with a nail or screw free deck surface. These systems are more expensive and time consuming to install.

Finally, there are a variety of framing connectors made specifically for connecting the various deck components. These can include joist hangers, post bases, post caps and stair brackets. Hot dipped galvanized and stainless steel connectors are a better choice than electroplated connectors because of their abilities to resist corrosion and provide good holding power.

It comes as no surprise that if you take the time to check with the pros at local building centers as well as product information sheets for specific fastener recommendations when using particular types of lumber in the framing of the deck as well as the addition of decking, etc., in the long run you'll end up with a well designed, strong and stable deck that will last for decades and provide you and your family with the ideal outdoor living space.