# How big an air compressor?



## Paola Alfa (Mar 7, 2014)

How big of an air compressor do I need to run a roofing type nail gun? I had been under the impression it had to be of a substantial size, well over the very small 2 gallon type I have. OTOH I have recently been informed that as long as I don't mind operating the gun rather slowly (that is, not trying to nail a whole row of shingles at once) even this small a size would be sufficient.

I am not thinking of a commercial operation. I am just trying to reshingle my own roof on a 1200 sf house. Would I probably be better off just using a hammer?

And what is a 2gl really good for. Can it run a small finish or cabinet nailer/brad driver or an airbrush?


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## A Squared (Dec 19, 2005)

Paola Alfa said:


> How big of an air compressor do I need to run a roofing type nail gun? I had been under the impression it had to be of a substantial size, well over the very small 2 gallon type I have. OTOH I have recently been informed that as long as I don't mind operating the gun rather slowly (that is, not trying to nail a whole row of shingles at once) even this small a size would be sufficient.
> 
> I am not thinking of a commercial operation. I am just trying to reshingle my own roof on a 1200 sf house. Would I probably be better off just using a hammer?
> 
> And what is a 2gl really good for. Can it run a small finish or cabinet nailer/brad driver or an airbrush?



Well, a couple of things: 

First off, the size of the receiver (the tank) is only part of the equation, the other part is the capacity of the pump. With a big enough receiver, you can use air in excess of your compressor capacity for a while, but you'll eventually run out. 

A small compressor will fire any nail gun ... once. Maybe a few times. I have a 2 gallon compressor which I've used to run a framing nailer. But if you try to drive more than about 4 nails in a row, you run out of air and have to wait for the compressor, which sort of defeats the purpose of a nailer which is to drive nails faster than you could drive them with a hammer. 

Of course the framing nailer uses more air per nail than a roofing nailer. But a fast roofer will shoot more nails. I don't think I'd try to do roofing with my 2 gallon compressor, but it will run a finish nailer or finish stapler faster than I can shoot nails doing trim work or other woodworking.


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## bbo (Feb 28, 2010)

if your compressor can produce enough cfm at the given pressure needed for the nailer it theoretically could run non stop.

If its close, and you aren't banging in rows of nails at a time, it should be able to keep up. having a larger capacity tank helps you go longer between the compressor kicking on. sometimes that's a clue to move some shingles in place, straighten things out, etc.

the ratings should be there for your model of compressor and also the model of nail gun you are using, you can probably look em up as needed on the 'net.


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## joecaption (Nov 30, 2011)

It may work but it would be running a whole lot if I was shingling.
The one I use is 3.5 gal. and works fine if just one person is nailing.
CFM (cubic feet per min.)is far more important then tank size.
Going to end up with a bunch of nails not setting to the proper depth if the compressor can not keep up.
An average roofing nailer uses .79 cf. to shoot one nail, you do the math.


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## oh'mike (Sep 18, 2009)

4 cfm @ 90 psi is good for heavy use----2.6 @ 90 is adequate for a worker moving slowly ----

Tank size doesn't matter as much as CFM--


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## ront02769 (Nov 28, 2008)

I have a little porter cable 6 gallon 2.8 scfi one that is easy to use and a larger PC double side stack. The larger one will run two framing guns at a time while the small one would choke on that. However, it will run ONE framing gun just fine assuming that I am not using it to nail off sheets of sub-floor or the like. It will also run a finish gun or a coil gun for roofing as fast as I need it, no worries. Ron


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## ratherbefishin' (Jun 16, 2007)

joecaption said:


> An average roofing nailer uses .79 cf. to shoot one nail, you do the math.


That actually is .079, not .79....big difference in one decimal, huh?. And that's Bostitch spec, Hitachi is much more efficient.:thumbsup:
But anyway, on a small roof like that, working alone, I wouldn't hesitate to give that little compressor a try. Even if it's a little slow, I'm pretty sure it'll be faster, and definitely easier, than hand nailing so long as it has enough psi to fire your gun effectively.


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## FullSwing (Dec 15, 2013)

Home Depot sells a Porter Cable pancake compressor for 99.00. and Its 3.5 gal. Its great bang for buck. I use this compressor for framing all the time. It cant run a crew but it can keep up with one guy no problem. Also nice and light. I run the thing constantly and has held strong for a long time. This compressor will do everything you would ever need it for.


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## A Squared (Dec 19, 2005)

Well, for what it's worth, I thought of this thread the other day when I was out in my shop, so I got out my little compressor hooked it up to a roofing nailer and shot some nails with it. 

What I found was that if I started with the compressor at full pressure, I could shoot about 10 nails before it started running, and it took about one minute to recharge from there. So I figure that the compressor could keep up with about 10 nails a minute, or 2 -1/2 shingles a minute, assuming 4 nails per shingle. I'm not a pro roofer, but I'm pretty sure that if I wasn't working on the edges and cutting shingles, I could lay more than 2 1/2 shingles a minute, so the compressor would be holding me back. 

My compressor is this one: http://www.amazon.com/Campbell-Hausfeld-FP209599AV-Twin-Stack-Compressor/dp/B000HDJHDG

As someone else pointed out the most relevant spec is the CFM of the pump, which for this compressor is 0.8 cfm @ 90 psi. 

Unless you're going to shingle really slowly, you might be happier with the porter cable pancake compressor someone else recommended


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## Maintenance 6 (Feb 26, 2008)

An interesting question would be "how many nails can you drive until the system flat ran out of air and the nailer wouldn't work?" Then "how long would it take to recycle so you could begin again?" After all you can't nail more than about 9-10 shingles before you have to move to another spot.


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## JustinK (Oct 4, 2009)

The most important thing is to make sure the nails are set all the way. When I first started construction I used a small compressor to put a porch roof on. When I was done and cleaning up I looked around and seen nails popping out everywhere through the shingles from walking on it. Not sure if the PSI wasnt high enough or I want pushing down hard enough or if it was just inconsistent air pressure.


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## A Squared (Dec 19, 2005)

Maintenance 6 said:


> An interesting question would be "how many nails can you drive until the system flat ran out of air and the nailer wouldn't work?".


That would be another interesting bit of information. Of course one thing to consider is that the nailed functioning isn't an either/or thing. but as you get less and less air pressure, the nails are less consistently driven, much like JustinK describes.


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## Maintenance 6 (Feb 26, 2008)

Right. And that would be the place that I would say the nailer no longer works properly and you need to wait for the compressor to catch up.


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## jeffnc (Apr 1, 2011)

Well don't forget, you'll be doing other things beside nailing shingles. You'll be cutting shingles, moving around, reloading the nailer, opening more shingles, stopping in a valley, etc etc. So even if you're doing 4 shingles per minute, you're only going to be doing maybe 3 on average (or whatever), so it's not always you waiting on the compressor.

I got that Porter Cable for $99 too. At the time it looked like a great sale, but I think they're selling for $99 everywhere. I still think it's a good deal, but not a great deal that I thought it was. If they're selling it for $99, it's probably worth somewhere around $99.


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## A Squared (Dec 19, 2005)

jeffnc said:


> Well don't forget, you'll be doing other things beside nailing shingles. You'll be cutting shingles, moving around, reloading the nailer, opening more shingles, stopping in a valley, etc etc. So even if you're doing 4 shingles per minute, you're only going to be doing maybe 3 on average (or whatever), so it's not always you waiting on the compressor.
> 
> I got that Porter Cable for $99 too. At the time it looked like a great sale, but I think they're selling for $99 everywhere. I still think it's a good deal, but not a great deal that I thought it was. If they're selling it for $99, it's probably worth somewhere around $99.


True, but the OP is talking about redoing a 1200 sq ft house. That's not huge, but unless it's got an unusual roof, there's going to be plenty of areas where you can nail shingles as fast as you can grab them from the stack, move a little and nail some more, if you've scattered your bundles first.


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## mako1 (Jan 7, 2014)

Easy answer here and numbers don't lie.Look at the specs on the nailer and see how many CFM it takes to run it then look at the compressor and see how many cfm it puts out at 90 lbs.


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## RoofingTrades (Apr 20, 2014)

Wow, I missed this thread. Question for you though. How many people shingling? Are you going to run a framing gun to replace your roof deck or nail down the existing sheathing? If you're just by yourself and you aren't doing anything with a framing gun, a cheap 4 gallon compressor 120psi compressor will do the trick. Try to get something oil lubricated as it will last longer. Unless you're really, really quick at shingling you won't be running out of air. You don't really need a shingling hatchet to shingle the entire roof when you have a compressor and gun at your disposal.

As far as roofing guns go, I recommend Hitachi NV45AE and the Max SuperRoofer. I've used every roofing gun there is out there and those are the best from all my years of experience and thousands upon thousands of squares I've pounded off. 

Any further roofing questions feel free to ask.


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