Author Topic: Nails for plywood floor  (Read 274 times)

0 Members and 1 Guest are viewing this topic.

Offline SouthernTier

  • Senior Member
  • ****
  • Posts: 209
Nails for plywood floor
« on: April 15, 2018, 10:29:29 AM »
For as common a task as nailing down a plywood floor (yes, I have started my build, will get a build thread started soon), I am having a hell of time finding the right nails.  I plan on doing this build 100% by the book (the book being 2015 IRC residential)

For nailing down (after gluing) 3/4" plywood, it seems like table 602.3(1) calls for 8d common nails , size 2 1/2" x 0.131"    However, it seems like all the nails available for air nailers are 0.113"diameter.  I guess this is a common problem with the air nails usually being box nail sizes. 

So I could either go with longer nails to get the diameter or not use air nailer nails.  But even that is a problem.  I could only find smooth shank 8d commons.  Aren't ring shanks preferable for the floor?  Perhaps I could get by with these: https://www.lowes.com/pd/Hitachi-3-in-21-Degree-Framing-Pneumatic-Nails-1000-Count/3247834 which actually are available locally.  Extra half-inch (which I know doesn't do anything for this application), but still only 0.12" diameter.

I can't find at the orange and blue big boxes 8d common ring shanks, and the other stores don't have their inventory online.   I guess I could get smooth shanks and swing the hammer (lowes has them), but would prefer ring shanks.

What do people use?  I know some use screws, but I don't think that is technically OK with the code, is it?

It looks like the box-size air nailer nails are OK for fastening the 2x lumber so long as the correct frequency is used, but it seems like whenever I am fastening plywood or OSB, I'll need common nails. 

Any suggestions?

Offline NathanS

  • Senior Member
  • ****
  • Posts: 540
  • NY Mountains
Re: Nails for plywood floor
« Reply #1 on: April 15, 2018, 10:51:24 AM »
Part way through framing I switched over to using the Wood Frame Construction Manual, which is the source for the code.

http://www.awc.org/pdf/codes-standards/publications/wfcm/AWC-WFCM2015-ViewOnly-1510.pdf

It's way more clear and easy to follow than the code book. When you get to roof overhangs and certain other areas of the framing the code might not have any info, but the WFCM will.

Table 3.1 pg 149 calls out 10d box nails

Also my personal experience with the foam subfloor adhesive is that it's an absolute mess and hard to use a can up before the straw starts clogging if you are working alone. I would use PL400. If you buy the professional ($$) straw shooter thing it probably works a bit better.

Also just want to add, I did use 8d sinkers on my subfloor and to attach all our sheathing, I just spaced them closer. Something closer to 4" edges and 8" center, then even closer on the overhangs, I think 3" or 4" everywhere within 4' of the end of the roof.. I can't remember if I actually interpolated that to be acceptable from the WFCM engineering section though. ;D I would not hand nail again, it's not worth the extra time. I do remember having similar issues with the code calling out nails that can't really be purchased anymore.

Don't use screws.
« Last Edit: April 15, 2018, 11:21:10 AM by NathanS »

Offline akwoodchuck

  • Full Member
  • ***
  • Posts: 141
  • Homer, AK
Re: Nails for plywood floor
« Reply #2 on: April 15, 2018, 11:29:03 AM »
I use full round head, 2-3/8" galvanized ring shank gun nails for wall and floor sheathing, and 3/4" subfloors. I try to adjust the air so that the nail head just barely sets, not blasting through the first ply....it's one of the few things in building that don't keep me awake at night... ;D

Offline SouthernTier

  • Senior Member
  • ****
  • Posts: 209
Re: Nails for plywood floor
« Reply #3 on: April 15, 2018, 11:30:03 AM »
Thanks Nathan.  Being in NYS, I hope you will follow my build thread when I get it up soon.

I have got the PL400.  Haven't used it yet.  Need the nails!

I don't know if my inspector will be checking the nails that closely, but I try to be conservative.  If the AWC is the source for the codes, would it be, in your opinion, OK to cite that box nail reference?  I know, the answer is to ask the inspector himself.  But curious to what peoples' experience is.

Offline NathanS

  • Senior Member
  • ****
  • Posts: 540
  • NY Mountains
Re: Nails for plywood floor
« Reply #4 on: April 15, 2018, 12:17:04 PM »
I will definitely follow along, looking forward to seeing your progress.

In chapter 3 of the code right up at the top it has the WFCM as an alternate provision.

I'm hesitant to say to much about pneumatic nail sizes because I was a moron and hand nailed the whole house. When you add it up it could have added a couple weeks to the build time. In general, manufacturers should have charts in pdf format that will tell you exactly how and what to use their hardware for, code approved.

Offline SouthernTier

  • Senior Member
  • ****
  • Posts: 209
Re: Nails for plywood floor
« Reply #5 on: April 15, 2018, 12:35:46 PM »
OK, think I am going to go with the box nails.  I have a great friend who is lending me his pneumatic.  I don't have a lot of time with a full time job, too many other hobbies (trying to cut back during the build), and an almost 1 hr drive to the site.  So I need all the time savers I can get.

Here's a sneak preview of the build.  This was last fall, as far as I got.  The floor was just temp-screwed in so I could tarp it up (with supports - more on that later) for the winter.  Got to pull the pieces up and fasten correctly.  Just ran out of non-raining weekends last year.  I didn't start my thread last fall since I wanted to make sure it made it through the winter OK.  It did!  No foundation cracking and plywood is as good as new.


Offline MountainDon

  • Administrator
  • Journeyman
  • *****
  • Posts: 16,634
  • Jemez Mountains, NM; that's pronounced HEY-mess
    • My 15.75 x 30 Jemez Cabin
Re: Nails for plywood floor
« Reply #6 on: April 15, 2018, 01:03:48 PM »
Calculating the cross-section area of the listed 8D common to the available box nails, the box nails have a cross-section area approx 25% less than the common nails. So use 25% more nails. As was suggested place them a little closer together when using a box nail equivalent.

It is important to NOT overdrive the nails. If the inspector is watching the details any overdriven nails will not count. If the nailer does not have depth stop then cut the air pressure.   Nails with clipped heads can also be a problem. .
Just because something has been done and has not failed, doesn’t mean it is good design.

Offline NathanS

  • Senior Member
  • ****
  • Posts: 540
  • NY Mountains
Re: Nails for plywood floor
« Reply #7 on: April 15, 2018, 01:16:47 PM »
Pic looks great. Has been a hell of a long winter.

Offline Don_P

  • Journeyman
  • *****
  • Posts: 4,289
Re: Nails for plywood floor
« Reply #8 on: April 15, 2018, 04:49:55 PM »
also check out 602.3(2), you will be exceeding that at 4&8" spacing. Screw shank is considered a deformed shank.

I had a discussion with Dr Nail, (Dr Bender) at VA Tech some years ago about ring vs screw shanks. If I'm hand driving I prefer a screw shank nail feeling that they provide better withdrawal resistance. A ring provides better initial resistance however once that initial pop happens its resistance drops to close to a smooth common. The screw has lower initial resistance than the ring but better than a smooth but does not drop off as much after that initial movement. My reply was the roofers and sheetrock guys stocking materials provide that initial pop.

Overdriven nails and spacing is the biggest thing an inspector will look for in sheathing.

If a squeak shows up later during construction I do use a screw, my shear has been satisfied, that is about withdrawal.

Offline SouthernTier

  • Senior Member
  • ****
  • Posts: 209
Re: Nails for plywood floor
« Reply #9 on: April 16, 2018, 03:58:08 AM »
Thanks Don.  Will be looking forward to your sage advice during my build.

Lowes had some 8d screw shank nails.  It didn't say, but looked like box diameter. 

But if I manage to grab my friend's air-nailer in time, I will probably go with the ring shank (https://www.lowes.com/pd/Hitachi-2-375-in-21-Degree-Framing-Pneumatic-Nails-1000-Count/3255210).

Either way I probably should go with the 4"/8" spacing.