Deck, Fence & Siding Fasteners

Unlike nails and other fasteners used indoors, those used to secure decks, fences and siding must be made to withstand the rigors of rain, heat, snow and cold. While it may not seem like nails would be susceptible to the forces of nature given how deeply they’re embedded, wood and other materials retain moisture that can seep through and rust and corrode fasteners, making short work of regular, unprotected nails and screws. Though galvanized nails and polymer-coated screws may cost a little more, you’ll be preserving both the appearance and structural integrity of decks, fences and siding over the long term when you use them. Keep the following questions in mind as you consider materials for your next project:

• What types of nails are available for outdoor use?
• What types of screws are available?
• What kind of coatings can fasteners have?
• How are nails sized, classified and packaged?
• What special features would you like to have?

Nails, Fasteners and Installation Considerations

Like indoor nails, nails used for exterior construction are classified by “penny” sizes. The origin of this term lies in England, where nails used to be sold in quantities of 100. If 100 nails cost four pence, they were “four-penny” nails, and if they cost ten pence, they were “ten-penny” nails. Today, the word “penny” helps indicate the length of a nail. Using the letter “d,” which is the English symbol for pence, nails are designated as 4d if they are four-penny nails, 12d if they are twelve-penny nails and so on. 2d nails are 1" long and subsequent measurements are given in 1/4" increments up to 10d (i.e., 4d nails are 1-1/2" long, 6d nails are 2" long, etc.). After that point, the system becomes a little trickier. 12d nails are 3-1/4" long, 16d nails are 3-1/2" long and 20d nails are 4" long. From there, each 10d adds another 1/2 inch, so a 50d nail is 5-1/2" in length. Nails are often sold in 1 lb. boxes, but they are also available in larger boxes, such as 10 lbs. or 50 lbs., and in bulk. The number of nails in each depends on the size of the nail.

Materials and Coating: Nails are frequently used for exterior construction applications. The designs are similar to their indoor counterparts, but nails designated for outdoor use are sometimes made from different materials or feature a coating that protects them from the elements. Stainless-steel and aluminum nails are ideally suited for outdoor use. Stainless-steel nails are more expensive and are somewhat softer and more brittle than other materials, but they are virtually impervious to rust and will last for long periods of time. There are two types available, 304 and 316. 316 stainless-steel nails should be used if you live in a particularly moist or humid environment, such as near the ocean. Aluminum nails are less expensive and are ideal for use with redwood and cedar. Avoid using copper or galvanized nails in redwood or cedar, as they will react with preservatives in the wood to cause damage. Coating is another way to protect nails from rust and corrosion. Zinc is the substance most frequently used to coat standard nails, and it is applied in a few different ways. The following chart details some of the different types of coatings used on nails and screws, how they are applied and a few points of consideration.

Coating Type	Process	Points to Consider
Electrogalvanized	Electroplating is used to coat nails and screws with a thin layer of zinc.	Less expensive Moderately effective Often used in conjunction with pneumatic nail guns
Epoxy and Ceramic	Screws are coated with a thin layer of epoxy or ceramic.	Moderately priced Offer reliable corrosion resistance
Hot Galvanized	Heated fasteners are tumbled through zinc powder or zinc chips, which bond to the surface.	Less expensive Coating is thin and may be somewhat inconsistent
Hot-Dipped Galvanized	Fasteners are bathed in molten zinc, which allows for a complete and thorough coating.	More expensive Available with varying levels of thickness Extremely effective

Fastener Types and Construction: Like their indoor counterparts, exterior nails feature different head and shank constructions. Larger heads provide more striking area while smaller heads are better for finishing jobs. Spiral, threaded and ring shanks provide extra holding power. Siding nails, which are long and feature small heads, have threaded shanks. Screws can also feature different heads, including square heads and Phillips heads. Square heads are less likely to strip and do a good job of gripping the driver as you insert the screw. Use galvanized staples to attach wire fencing to posts and galvanized soffit nails for work on the underside of a structure.

• Stiff-stock A/T pole barn nails provide superior holding power in load-bearing structures and feature threads that lock into wood fibers for additional strength
• Galvanized spiral patio nails have a spiral shank and are used on pressure-treated wood
• Other head types include box, casing and siding
• Polymer-coated screws resist both rust and corrosion
• Sharpened deck screws eliminate the need for a pilot hole

Installation Considerations: In addition to being able to resist rust and corrosion, it’s important to choose fasteners that are nonmagnetic, as magnetic nails can have adverse reactions with other nearby metals. In some cases, you may need to drill a pilot hole before driving nails and screws, particularly when you’re working close to the edge of a piece of wood. This will help prevent wood from splitting. Temperature changes cause vinyl siding to expand and contract, so you’ll need to leave a tiny bit of room between the head of the nail and the siding to compensate for this movement. Remember that salty sea air speeds up the corrosion process, so take extra precautions when working outdoors near the coast.

• Blunt nails are harder to drive but are less likely to cause wood to split
• Nails can be blunted by tapping the points with a hammer
• Siding nails may either be countersunk or hidden with a coat of paint
• Railing posts may require stronger fasteners, such as hex bolts, nuts and washers
• Make sure the nails and fasteners you use comply with local building codes

Features

Lubricated Screws: When you’re driving screws into a particularly hard surface, lubrication can help them slide in with a little less effort, saving you time and energy.

Checkered Heads: Nails with checkered heads reduce the chances of the hammerhead slipping off as you drive in the nails, making them ideally suited for framing applications where it’s important to avoid damaging the surrounding area.

Pneumatic Nailer: For heavy-duty jobs that require a lot of nailing, you may want to consider a pneumatic nailer. These automatic devices not only save wear and tear on your arm, but increase speed and accuracy as well.

Hidden Fastening System: Some decks, particularly those made from composite materials, may feature hidden fasteners that are inserted between the board and joist for a clean finish without any visible nails.

Self-Countersinking: Deck screws that countersink themselves make it easy to achieve a smooth, clean-looking finish.