This seems to be a question I get asked a lot, I do use both depending on what I’m doing. I like screws for their holding power, but I use nails and brads in my air powered tools.
Either nails or screws can be used for attaching plywood. Screws are usually recommended for plywood used for flooring, as it will help to prevent squeaking. The general rule of thumb is that whatever type of fastener you are using, the fastener should be at least three times the thickness of the material used, so that’s something to keep in mind.
What Nails Do You Use for Plywood?
Different types of nails can be used, depending on what you are doing with the plywood. The lengths of the nails are determined by the material underneath the plywood.
Framing nails are generally recommended for most plywood applications. These are good for both indoor and outdoor use. They are also called box nails or common nails. Box nails are thinner than the others to help keep the wood from splitting while they are being driven. They are really designed for solid wood boards, not plywood.
Common nails are the least expensive but tend to start to loosen and pull up due to plywood shrinkage. Another type is the sinker nail, which has a waffled head and a coating over the shank which is designed to help keep them in place. This is the best type of framing nail to use for plywood. Check out my article What Are The Best Types of Plywood For a Shed? if you need help choosing your plywood.
Can I Use Brad Nails for Plywood?
Brad nails are actually made from 18-gauge steel wire. The small diameter makes them easier to use, but many people just use them to hold glued pieces together until the glue dries. Since they also have a smaller head, they are often used in furniture, paneling or other interior work where it is desirable to make the nails less visible. Since these nails are thin, they work well with plywood.
However, these nails are not meant for the heavier work of construction, such as building your shed. Since you will be using thicker plywood in some areas, such as flooring, you’ll want a heavier nail that will do the job and hold a long time. The nails may tend to bend more often when nailing the thicker plywood unless you are using a nail gun.
Will Finishing Nails Hold Plywood?
Finishing nails are named for their purpose. They are used mostly for lighter carpentry work, such as trim, baseboards, crown molding, stair treads and risers, cabinets, and other light, mostly interior work. While they will hold plywood, be sure to get the heavier type. Another problem with finishing nails is that they have a small head, which can eventually allow the plywood to pull up.
While the small heads are fine for interior work which will not get much wear, finishing nails are desired to make it easier to hide the nail heads and holes. On a build such as a shed, you want nails that are sure to hold your plywood in place, especially since you hope to use your shed for many years.
Can I Use Screws for Roof Sheathing?
While most people prefer nails for roof sheathing, screws can be used to attach plywood sheathing, but you’ll need to ask your supplier about the size you need. The thickness of the plywood used (usually a 2 ½ inch for roof sheathing), along with the local weather will help determine what size screws to use.
Screws generally will hold plywood more firmly than nails. Another advantage is that nails will sometimes miss the joist when nailing while screws if missed will not countersink letting you know it has missed the rafter.
Can I Use Drywall Screws on Plywood?
Just about any source that can be found on the subject will tell you not to use drywall screws on plywood. There are separate drywall and wood screws for a reason. Drywall screws were developed originally to provide a rapid method of attaching drywall to metal studs when installing it in commercial buildings. They were designed for speed economy.
The fact that these screws have threads along the whole length means that there is a tendency for the two substrates attached to slowly work themselves apart during natural expansion and contraction and other stresses.
Because these screws were designed to go into metal, they are very hard, but with that hardness comes brittleness. They will snap off if they are screwed in too tightly. They can also snap off under excessive stress. Just something heavy dropped on a floor secured with drywall screws can eventually cause the screws to snap.
With the stress placed on a plywood floor in your shed, drywall screws would not be suitable. Considering the failure possibility and the tendency to have the substrates pull apart, it would be a much better idea to use wood screws for the purpose.
How Far Apart Should Screws and Nails Be in Plywood?
Generally, nails and screws should be spaced six inches on center along the plywood panels edges, and twelve inches on the studs or joists on the interior of the panel. On flooring, you may want to space them even more closely for extra stability. Also make sure your installing your plywood correctly, take a look at my article What’s the Correct Direction for Installing Plywood? to be sure your not making these mistakes.
What Size Screw for 1/2 Inch Plywood?
For half-inch plywood, a #6 screw 1 ½ inches long is generally used. When using screws to install plywood, you may want to drill pilot holes to help keep the plywood from splitting. On this size plywood, the pilot holes should be 1/8 inch wide.
How to Choose Correct Size Nail or Screw?
Nail lengths are generally figured by choosing a nail three times as long as the thickness of the material you are nailing. Since there are so many types of nails and screws to choose from and each has various sizes and thicknesses, the best way to find out what size and length you need is to consult your supplier.
Be sure to tell him exactly how and where you plan to use your plywood. There are also charts available for plywood which will tell you what size you need according to the thickness of the plywood. They will also tell you what size pilot holes you will need to attach screws.
Can I Use Screws on OSB Sheeting?
OSB stands for oriented strand board. It is engineered wood with similarities to particleboard. It is formed by adding adhesives to wood chips, strips and flakes arranged in specific directions, with layers perpendicular to each other. The board is then compressed. OSB is more popular than plywood in some areas.
Some sources consider it to be stronger in some ways than plywood, while others’ testing results rate them as having the same strengths. As far as building codes, both OSB and plywood are considered to be wood structural panels, and so are interchangeable as far as building codes.
While OSB is typically coated to withstand moisture and some is rated waterproof, it does have more problems with moisture than plywood. The edges are not treated, and once they swell due to moisture it is a problem that can’t be fixed. One cause is that water and moisture take longer to respond than does plywood, but conversely, it takes longer for that moisture to leave.
The longer the moisture remains, the more likely it is to rot. The kind of wood used in its construction has an impact on this tendency as well. A good way to prevent problems is to cut all your OSB to size first, then use waterproofing on all the cut edges.
As far as fastening, for a subfloor it is recommended to apply construction adhesive along each joist, then lay the panel on the joist. Use #10 2 ½ inch wood screws to fasten, spacing them six inches apart along the edges and twelve inches apart throughout the rest of the panel. For other applications, the manufacturer or supplier should be able to give you advice.
Tips for Using Nails and Screws
Storage – You can store a few leftover nails, screws, or nuts and bolts in old prescription bottles. Scraping off the label will help you see what’s inside. This is much better than dropping them into a jar with the different sizes and types all mixed up. Sandwich bags will also work, but screws and nails do tend to punch through these thin bags.
There are all sorts of products that come in smaller containers, such as olives, small jars of instant coffee, drink mixes, etc. These all work to keep your fasteners stored, and the transparent ones take the guesswork out of identification. Of course, labeling your containers helps considerably.
Nuts and bolts can be kept together by attaching the nut to the bolt part way before storage. Use beeswax or a lip balm on the bolt threads to prevent rust for long-term storage.
While taking something apart for repair, use a jar lid or small container such as that from sour cream to drop them into while you are working. An old spice rack with jars would be ideal. You can label your fasteners by writing the size on masking tape, then putting it on the bottle. Note – it’s a lot easier to write on the tape while it’s still on the roll, then tearing it off.
For more complicated items such as those requiring different fasteners in different places, you can use a piece of foam board or corrugated cardboard. Insert your nails or screws into the board as you take them out. Writing down on the board the places the fasteners came from will help you get the right ones in the right place.
Screw sticking – If you have a hard time driving your screws, use a chunk of beeswax or lip balm to lubricate the threads before using. If you are working on something already built and trying to remove some screws, you may find that the screw head slots are worn, especially with Phillips head screws. To counteract this, put a piece of wide rubber band flat over the screw head. Stick your screwdriver tip into the head through the rubber. The rubber band should provide traction to help you get that screw out.
On a ladder – Keeping track of fasteners while on a ladder has always been a problem. Attaching a magnet to the top of the ladder will help keep those fasteners corralled. Some magnets even have a sticky side with a peel-off strip. Another choice is to use that sour cream carton with a hole cut into each side near the top edge and running a string through to create a kind of small pail. A paper clip or Christmas ornament will hook your pail to a ladder support.
Typical uses for nails – Nails are more flexible under pressure, while screws, especially long ones, can snap. This is why nails are used for structural joining of materials, such as framing. When needing thinner fasteners, such as on furniture, thin nails also hold up better than thin screws. Nails also have the advantage of not necessarily needing to have a large head, making small-headed nails ideal for furniture and other inside jobs where it is desirable to hide the nails.
Nails can be easily hidden by countersinking with a nail set tool. This is a tool with a tapered tip, rather like a punch. You can get a set that includes different sizes. Once the nail is pounded in, use the nail set to pound it in until the head is below the material surface. The hole that’s left can easily be filled in with wood filler to create a smooth surface.
Typical uses for screws – screws are favored for temporary jobs because they are easier to remove. They also form tight bonds. Because attaching screws causes less vibration than using nails, they are also good for installing materials that are more delicate, such as drywall.
Screws also are better at preventing attached materials from working loose or separating with time or vibration. They are also better at withstanding shear, which is caused when two attached surfaces try to slide past each other. If screws do work loose, they are more easily tightened back to normal than are nails.
Basically, nails and screws are like any other tool. For each job or part of your job, you pick the fastener that will work best with your materials and what you are doing with them. Large building projects such as sheds often use both.