A lot of roofing companies have tried pneumatic nail guns at one time or another for composition shingle installation. (These high powered guns shoot real roofing nails by the way, not the infamous staples.)
These guns are great for nailing down wood decking, which is usually either plywood or OSB board (also called wafer board). But most roofers ultimately become disillusioned with using air guns for nailing shingles.
If you decide to use a roofing company that favors guns, ask them to at least slow down a bit when they do your job, and tell them you’re concerned about the quality of the nailing.
The potential for high-powered pneumatic air guns to save money by speeding up the roofing process and trimming labor costs is pretty significant.
And who would benefit more from these automatic weapons of the construction world than roofing companies? Roofing crews often install from 75 – 100 lbs. of roofing nails per job, per day. And all by hand.
So what’s the problem then with using nail guns to install composition shingles? Besides the fact that most roofing crews can’t afford all the gear required? And they prefer the craftsmanship and control of an old-fashioned roofing hammer anyway?
The main problem with these high-powered air tools is just that – high power.
Although the air pressure of a nail gun can be adjusted by the individual shooter to (theoretically) ensure quality control over nail penetration, when it comes to composition shingles perfection is elusive.
For example, nail guns can easily drive fasteners too deep, perforating and tearing the somewhat fragile surface of composition shingles. This can seriously compromise the integrity of the entire roof installation if these faulty areas are left uncorrected.
Composition shingles contain asphalt, and as air temperatures fluctuate throughout the day, the asphalt in composition shingles is constantly heating up and cooling down. This affects the texture and thickness of the shingles (cold shingles mean a harder nailing surface whereas hot shingles are more malleable), and air gun pressure must be continually monitored and adjusted accordingly.
Nails should sit flush with the surface of the shingle. Problems can occur, like shingle blow-off for example, when nails are either over-driven, crooked, or left protruding. (Unfortunately all of these scenarios are distinct possibilities with nail guns.)
Also, air guns can’t distinguish between solid wood and a ‘void,’ or crack, in the decking, resulting in loose nails that can eventually work themselves back out and cause trouble.
For these and other reasons inspectors, like TWIA for example, have a harder time certifying composition shingle roofs that are gun-nailed, especially in areas that are deemed ‘high-wind’ (like the Gulf Coast).
Finally, air guns and compressors are extremely noisy, they require constant maintenance, and they’re heavy to transport.
We’ve used nail guns at Ernie Smith & Sons Roofing in the past (many years ago). They’re pretty neat, and they save a lot of time and energy. But if you have to slow down every second or third shingle to adjust air pressure and correct nailing problems – all by hand of course – it kind of defeats the whole purpose.