All Things Gypsum: Nails, Screws, And Adhesives
February 28, 2011
Last year, one of my frequent golf buddies called me in a panic: two corners of a small piece of wallboard attached to his garage ceiling had come loose. Could I come over and look at it before it fell on his car?
I cruised over to his house and quickly figured out that whoever installed the board completely missed the ceiling joists on one end when he or she fastened it to the ceiling. When my friend decided to store some heavy boxes on the joists, they bowed a bit and the “friction-fit” that held the corners of the board in place was compromised. While the board probably had been in place for 25 years, the joist movement caused the corners of the board to slip and the unattached end dropped down a few inches. We fixed it with a couple of properly installed screws and a catastrophe was averted. My buddy was happy.
A few months ago, my friend mentioned to me that a contractor working on his house thought very little of our screw installation solution, because “no one ever uses screws to attach drywall because they don’t work.” The contractor’s proof was in the situation that had occurred in the garage: “had that board been installed with nails, this never would have happened.” I patiently explained that a whiff is a whiff and if nails had been used to install the board and they had they missed the framing members, the board still would have slipped. I also mentioned to my friend that the use of screws to attach drywall is an accepted practice and that he might want to search for a different contractor; one who is a bit more up to date on modern construction techniques.
But the entire escapade also got me thinking about the merits and drawbacks to the three generally accepted methods of attaching gypsum board to framing members: nail, screw, and adhesive attachment. Each attachment method has positive attributes but each one deserves some thought.
NailNail application is the oldest attachment method for gypsum board. The first sheets of rudimentary gypsum board developed in the 19th century were attached to wood framing members using nails, most likely using a type of coated cooler nail. In the current market, cooler nails and similar coated fasteners, have largely been replaced by ring-shank drywall nails.
The principal appeal of nail attachment is the simplicity of installation. With a handful of nails and a claw hammer, anyone can install gypsum board. Like a screw attachment, it also has broad acceptance in fire and sound testing as most lab tests are run using either nails or screws.
The primary downside to nail attachment is the potential for nail pops. Nail pops are primarily caused by the use of initially high moisture content lumber and can be compounded by the use of overly long fasteners. To be fair, it should be noted that you can also experience fastener pops with a screw application. However, the occurrence is less likely. A bad outbreak of nail pops looks like a case of the chicken pox on a wall or ceiling and it is a condition that can take a year or longer to be exposed. It also can be exacerbated by the misapplication of fasteners, specifically when nails are not seated properly against a board, or, as in the example above, they are not correctly embedded in the framing member.
Another drawback to nail application is the obvious limit on use with metal studs. While mechanical fastening tools that install nails into metal studs have been developed and are gaining broad acceptance in some markets, they typically remain somewhat out of the reach of the average homeowner who simply needs to hang a few of sheets of board in a new basement closet.
ScrewTherefore, despite the contractor’s misgivings noted above, screws are commonly used to attach gypsum board. They require a bit more sophistication to install than nails-you have to be adept at the operation of a screw gun-and a source to power or re-charge the tool used to attach the screws; however, screws offer many benefits over nails.
First, if you learn how to properly operate a screw gun, you can set the tool so that the screws are driven into the framing members at a uniform, consistent depth. This helps to limit overdriving the screws into the board and tearing the face paper or damaging the core of the board. Properly set screws also eliminate the need to dimple the face paper, as has to be done with nails, to facilitate finishing.
Second, although they can still occur, you typically don’t get as many nail pops with screws as you do with nails. The primary downsides to using screws are that they, like nails, can rust if the coating is chipped off or removed and the fastener is exposed to moisture. They can also be difficult to remove if the head is damaged during installation or replacement.
AdhesiveAdhesive application of gypsum board is an alternative to mechanical fastening and is widely used in many housing markets in the United States and in manufactured housing. The upside of adhesive use is clear; with few or no fasteners involved, the potential for fastener pops is greatly reduced or altogether eliminated and there are no fastener heads to finish. Adhesives also can permit a direct application of board to monolithic surfaces, such as masonry or concrete without the need to install supplemental furring. It is surprising how tenacious the grip of a simple adhesive to clean, well-prepared masonry surface is.
Paradoxically, that positive attribute-the holding power-is probably the primary downside of adhesives. When using adhesive to install gypsum board, you better be sure that the board is where you want it to be before the adhesive sets, because when it does set it can be quite difficult to remove the board from the studs. I have seen situations where the set of the board to the framing members is so strong that the studs broke when an attempt was made to remove the board. In addition, when the board is removed some of the adhesive remains on the stud and has to be removed before a new facing layer can be applied.
An adhesive application is fast, efficient and makes the finishing process easier and faster; however, as with any application method, you have to know the limitations involved. Installing nails is simple and easy but nailing probably is the application method that is also the easiest to do incorrectly. Screws are a breeze but you have to know how to correctly operate a power tool to reap the benefits.
All three methods have benefits and limitations that need to be evaluated before the job begins.