To nail gun or not to nail gun?

[Stephen Tashiro]

I'm going to put some 5/8 inch sheeting on the roof of a storage building. It has a flat roof and I'm tempted to use my Hitach round head pneumatic nail gun and 2" nails. But to build the slope into the roof, a beveled 2x4 was nailed on top of the joists, so the heads of these nails are a hazard that I can't see when I would be nailing the sheathing.

How bad would it be to hit one of these nails when using the nail gun?

[Jamie Buxton]

It isn't a very big building, is it? That is, if you hand-nailed the sheeting, how much longer would it take you to do it?

[Stephen Tashiro]

It would take about 14 sheets and I can easily do it by hand. But I like using powered tools and it would be interesting to use the nail gun on the sheathing if I'm not doing something dangerous. So far, I've been very cautious about using it. I don't mind a few bent nails or U-turns. But I don't want to risk worse disasters just to satisfy curiosity.

[Bob Aquino]

Generally, if you hit a nail, it will deflect the new one a bit. Worst case is a blowout where the nail makes a sharp turn and pops out the side instead of going straight down.

If you mark where you are going to shoot the nails with some chalk lines, you should be fine. Only real downside to nailers, is that you cant tell when you missed the wood underneath as you would with a hammer.

[Russ Boyd]

Be sure you are using the proper nail. Galvanized or the like is the right choice. Moisture can get to the nails even under roofing. Staples would be the preferred choice if possible. Keep a light hand on the nailer so if you hit one of those "hidden" nails it won't jam the gun.

[Rich Engelhardt]

Hello,

Only real downside to nailers, is that you cant tell when you missed the wood underneath as you would with a hammer.
Actually, you'll know right away if you miss.
The nail blows through the sheathing like it was made of paper.

Anything below is in serious jepordy of being killed or injured.

Framing nailers are designed to be used on framing stock, not thin (3/4" or under) materials. For thinner materials, you really want a fastener with a larger head.

The other drawback to a framing nailer is that they bury the head too deep in the sheathing. For roof sheathing, you want the head just slightly below the surface & a bit on the "loose" side.

I'd suggest putting up the framing nailer & either going with a palm nailer - if you want to have some fun - or doing it by hand.


Edit to add:
W/5 houses, I do a fair amount of framing new to old. It's not uncommon to hit nails (as well as "other things") in old work. My Bostitch F28WW just keeps on humping, which is one reason I paid so much for it. I can't say how your Hitachi will handle it & if it's hammer is up to it w/out breaking. (The F28WW is rated for concrete and masonry).
Anyhow, when a nail or screw or anything else is hit, the gun just kicks back more than normal. A lot of times, the nail head will stand proud of the surface also. A few whacks with a hammer or shots with the palm nailer sets them flush.
I've probably hit a few hundred or more in the last few years. it's not common, but it's not uncommon either.