Hello dopers,
I was wondering the other day – it seems that nails are ubiquitous as wood fasteners in all sorts of wooden constructions. In places where I would intuitively use screws. I can think of two reasons nails would be used – cost and elasticity. Is that why or is there other benefits to nails I’m not aware of?
Best regards,
Groman
From my experience, nails are also faster, especially with a nail gun. You can’t just fire a screw straight into a piece of wood, or else it’s really no better than a nail.
I remember my dad explaining to me that screws are preferable when there could be traction of the joined pieces, because the grooves dug by the screw would hold it in place.
Not sure whether it is the whole truth, but there you go 
Nails are more convenient. To properly set a screw you must drill a pilot hole and sometimes, depending on the head type, countersink.
Nails are neater and less noticeable when applying a fastener to a finished area like molding or finished panels.
But screws are stronger, and less likely to back out over time. Screws for furniture, Nails for stud walls and decks. There are also some great glues (rooglue) available now that make screws/nails unnecessary for finished work.
About 10 years ago a contractor had to repair (more like rebuild) a ceiling joist that had undergone a lot of damage. He repaired it by securing a section of a new joist onto the old joist by using nuts, bolts and washers. I was very impressed.
Just speaking off the cuff I’d say as a general rule, by order of increasing strength the fasteners would be:
• nails
• screws
• nuts and bolts
Nails are fine when A) they are strong enough, B) you’re not worried about slight shifting of the nail head through wood expansion/contraction, and C) there’s no pulling force on the surfaces the nail is holding together.
A perfect example of a good application for nails is in wood framing in houses. A couple of nails holding a framing member to a floor plate and header is fine, because there’s really very little force applied to these. They’re not structural, and once the drywall is up a composite structure is formed when the dryall keeps the framing members from shifting, and the framing members give the drywall rigidity. Nails are fast, so why not use them?
On the other hand, if you’re hanging ceiling joists, you want to use screws because the pulling weight of the joist will eventually cause the nails to pull out. And you want to use screws on drywall, or else over time as the framing members swell and contract the nail heads will pop out and ruin your wall finish.
Nails are just about as strong as screws in shear force (i.e. if you have two surfaces nailed together and you try to slide one across the other, the nail will hold very well). But if you’re pulling the two surfaces apart, the screw is much, much stronger.
Does anyone really use screws on drywall? Most every place I have seen uses nails.
This guy tells of why screws are so much better than nails for hanging drywall. Unless drywall nails are much faster than screws (and with those fancy screw guns with magazines of screws it’s pretty quick), I don’t see why contractors would use nails anymore.
Another big advantage of screws, you can take them out much more easily than nails - something you might want to do if you have an access panel.
Googling “drywall screw” returns 473,000 hits.
I don’t know anybody that would use nails to hang drywall and I know many builders.
I may have to disagree with you here Sam. If the screw has threads all the way up past the joint between the two pieces of wood, a nail would be stronger in shear. Placing screw threads in shear is a really bad idea. The threads cause a stress riser and make it very easy for the screw to shear off. A nail on the other hand has a smooth shank and no place for a stress riser to start. (Ring shank nails being the exception.)
I used both on the plasterboard ceiling in my garage - I started with nails, then switched to screws when I decided all those hammer marks were unsightly (from all the times I missed the nail - it’s not easy nailing into a ceiling)
Well, that’s what mud is for, but screws are better and easier anyway.
Not to mention that the reduced cross-section caused by the threads means that even if the fasteners were made of the same material, at a given diameter the nail will always have a larger shear area and thus greater shearing strength. IIRC many screws are hardened, which increases strength but also makes them more brittle - for example drywall screws tend to snap whereas nails bend.
Screws do have better pullout resistance since the threads lock them in place while a nail has to depend on basic friction.
Here in California, with some particular exceptions, you can’t install seismic reinforcement (Simpson Strong Ties, etc) using screws, you have to use nails. When I did the shearwalling in my house (fastening sheets of 5/8" plywood to the framing) I was required to use nails, not screws. Shearing strength is the concern, not pullout of the fastener.
ETA - I’m not a contractor but I did a bunch of drywalling in my house and I found one situation where screws were the wrong fastener for the job whereas drywall nails were perfect, and that was installing cornerbead. Screws made a mess of the metal bead, really bent it out of shape because the bugle head can’t sink into the surface like it does with paper (without distorting the bead a lot). Drywall nails OTOH were just right.
Even without the fancy screwgun this article describes, screws are faster for anyone who is not used to nails. You can buy philips bits that have a collar on them that sets the screw at the proper depth. They’re cheap, and can be used in any screwgun or drill. It’s easy to start the screws with one hand, as the bit holds the screw in place. Nails can be easily over-driven, crushing the drywall, and they are more prone to popping out. Around here, it’s very uncommon for anyone to use nails.
With the exception of some old-timers who can probably work very fast and still do a quality job with nails, the only advantage I can see to using nails is cost.
agreed. I saw a LOT of drywall installed after Katrina. No one I remember used nails. The problem with nails is that they are very poor at resisting tension. Over time they will pull out as mentioned up thread. About the only force on a drywall is pulling away from the stud. Over time the nails will pop. Screw em every time (sorry couldn’t resist).
I suspect that the advent of the cordless drill/driver made nails obsolete for drywall work.
Mr. bink and I tore down the sheetrock from our garage ceiling today. They had used a combination of nails and screws. Both held the ceiling up just fine, but I have to say the nails were a LOT easier to remove from the beams!
I wish I could find the reference I read a few years ago, but I can’t, so I’m just going on memory here…so beware, take w/a grain or two or salt, but IIRC, an article I read said that the extra cost of drywall screws versus nails was about $300 for an average size house.
I have no idea what constituted an “average size house” as the article didn’t specify.
For a second data point, in my area you would not believe the lengths contractors go to in order to save a nickel. I won’t go into BBQ Pit detail, I’ll just say that my house was built in 1989 by one of the best builders int he area, and when I tore down one bathroom wall to enlarge the bathroom, not one drywall panel had a screw, it was all nails. Furthermore, the bathroom had regular drywall, not the “green” wall or whatever it’s called that is moisture resistant than regular drywall and is supposed to be used in moisture-prone places like bathrooms.
So I totally would believe that some contractors would use nails instead of screws solely because of the slightly greater cost.