By Michael Davis

Specs and Tester's Tester Comments

As a production framer building large-scale projects, I could probably measure the amount of plywood subflooring and decking we install in terms of acres. And while most framers still use pneumatic nailers to fasten their subflooring, the argument for screwing and gluing plywood to joists, based on reduced callbacks for squeaky floors, is strong. So we were especially interested in testing the latest batch of autofeed screwguns to see if we could maintain our speed and increase our quality in a production setting.

Autofeed screwguns basically come in three flavors: small one-handed tools for drywall and backerboard applications, versatile crossover models that come with extensions so they can be used to install subflooring from a standing position, and dedicated standing-application subfloor and deck models.

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The telescoping extension handle on Senco's DS300-AC has detent settings for length adjustment. A side handle would improve comfort during use.

Credit: Photo: David Sharpe

Versatility is the key word, though. These tools can be used to screw just about anything to just about anything else, and the manufacturers make screws for just about everything. There are screws for fastening drywall and plywood to wood or steel; special screws for ACQ-treated wood and composite decking; zinc-plated, galvanized, and stainless steel screws for exterior applications; and finish-head screws for interior jobs–to name just a few. You can find a use for these tools in just about any phase of construction, from framing to tile prep and everything in between, so we decided to limit the scope of this test to tools that could be used in a standing position for installing subflooring and decking.

The autofeed screwguns we tested basically operate like lower-speed versions of drywall screwguns, except they have specially designed nose attachments that work with collated screws. The screws are pressed into a strip or coil that feeds into the nosepiece of the tool. As each screw is driven, the tool automatically advances the strip, placing the next screw into position for the drive bit.

This is not to say that you can't bend over and install subflooring with one of the smaller tools. In fact, a number of people I spoke to said they prefer to do just that. They felt that leaning down to place the screws was just as fast and far more accurate. Bending over does put you closer to the work, giving you a better line of sight, but if you're running acres of floor deck, I think your back will eventually convince you that an upright model really is the way to go.

The Tools

The autofeed screwguns we tested are the Makita 6834, the Muro CH7390 and FDVL41, PAM Fastening's P13KUE Universal Extension System, the Senco DS300-AC and DS300-S2, and the Simpson Strong-Tie Quik Drive PROCCSM35K (the Makita 3,500-rpm motor option). We also tested one tool that is produced and sold by two companies under different model numbers, either as the Grabber 7526HXT SuperDrive or the Hitachi W6VB3SD SuperDrive.

The Grabber/Hitachi, Makita, Muro CH, PAM, Senco S2, and the Simpson Quik Drive are what I'd call "crossovers," compact tools that would be great for drywall or any one-handed, close-in application and can be easily transformed into admirable stand-up subflooring tools. The Grabber/Hitachi, PAM, Senco S2, and Simpson Quik Drive accomplish this by adding an extension between the motor unit and the autofeed mechanism. The Makita and Muro CH make the switch by adding an extension handle to the rear of the motor unit.

The Muro FD and Senco AC are what I think of as "dedicated" subflooring installation tools–tools used only with the handles attached. Both are serious production tools.