How do you know when it’s better to use a nail or screw?
Ah, the eternal question! Unlike the Coke or Pepsi debate, nail or screw does have a correct answer – many correct answers because it depends on the context.
In general, nails handle shear weight better than screws. When you’ve seen a screw head pop off while driving them in, you know they can be brittle. So when it’s a structure that bears weight, remember that a nail will bend while a screw can snap.
A screw is more easily removed after it’s in place, so it’s more forgiving with works in progress. And screws are easier to apply to an exact location. But because they are typically wider than nails, they can split soft wood, and do require drilling a starter hole to screw them in properly.
Nails enter a material cleanly, and when they have a tiny head, can be buried under the surface of wood and filled in. This is why they are used for fine carpentry and visible framing work. But if you’ve ever tried to remove a nail you know the mess it can make.
Context is important when deciding which to use. When it’s a project where weight or gravity bears down on the fastener, a screw holds position better than a nail. If the fastener will bear more side-to-side movement or needs some give, a nail is the better choice.
Building a deck is a good example of how gravity, weight and movement influence the decision between nail or screw. Use nails to attach joists to the deck framing. Use screws to fasten down the decking.