The Fastener Depends On The Application
Some of you may not be sure which is the right fastener for your do-it-yourself project – nails vs screws. The truth is that they both have their place in construction, so it does depend on what you’re working on.
If you are doing basic construction such as attaching floor joists to deck framing, nails are the best fastener. Nails are used in most all framing and structural situations.
The time to use screws is when you are building something where forces will be applied in a parallel direction. In accordance with the above example, screws would be better for fastening the decking to the frame.
Shear Strength vs Tensile Strength
The general rule is that you use nails when the pressure will be perpendicular because of their shear strength, but you use screws when pressure will parallel because of their tensile strength. There are a lot of conflicting opinions out there, and this site allowed several experts to chime in.
I tend to agree with this statement:
Screws are a “superior” fastener over a nail (they have far superior tensile strength)—especially if you’re talking about screwing down decking. However there are many scenarios where a nail is the proper fastener for the application (attaching joists is one example—screws are brittle and will fail when subjected to the forces of a shear loaded application).
Hanging a picture versus building a deck require vastly different fasteners. The hardware aisle can be a little intimidating with the wide variety of nails and screws, but the type project makes all the difference.
Are you hanging sheet rock, putting in a fence, finishing trim, siding your home, or roofing?
If you prefer a visual demonstration of the difference between screws compared to nails, this video is an excellent example:
The above video is a complete show of shear strength because the motion he is using is perpendicular to the surface. If he tried to pull straight up on the two fasteners, the nail would come out but the screw would not, mostly because of the threads.
Other Reasons To Choose One Fastener Over The Other
The cost of the nails vs screws in construction is an entirely different story. Part of the reason construction contractors use nails is that they are significantly cheaper to use than screws.
Another explanation for using a screw instead of a nail is that you can easily take a screw back out, especially in a temporary situation. Nails are quite permanent, at least without some major destruction.
Of course, the type of nails and screws can make a difference, because galvanized fasteners are more expensive since they are made to resist rust. All in all, you probably want to consult with a Denver builder contractor to discuss what materials will work best for your situation.