Is there a standard that shows for a given nail size and nailing pattern, say for floor or roof sheathing, an equivalent screw size can be used? Thanks for the help.
Discussion Forum
Discussion Forum
Up Next
Video Shorts
Featured Story
Skim-coating with joint compound covers texture, renews old drywall and plaster, and leaves smooth surfaces ready to paint.
Highlights
"I have learned so much thanks to the searchable articles on the FHB website. I can confidently say that I expect to be a life-long subscriber." - M.K.
Replies
Oh Canada
Going to work for "Holmes on Homes" ?
Depends...
These things are governed by building code, so it depends on which building code is adopted in your state. I looked at your profile and I see you live in VA so I'm pretty sure it is 2006 IRC – same as here in NC. Unfortunately the IRC is a copywrited document so it is not on the internet – that I know of. In the IRC code there is a table in the wall chapter that gives the fastening schedules (nailing patterns) for various structural connections. Fastener schedules depend on what wind speed area you live in - ie for example costal areas that are hurricane prone will have more stringent requirements for structural panel fastening. I'm sure sizmic areas (earthquake zones) have special requirements too. It also depends if we are talking about wood structural panels or other material.
All that said, I'm gonna guess that you are in the same wind speed area that I'm in which is 100 MPH. For us structural panels need to be fastened every 6" on the supported edges and every 12" in the field. There are some assemblies that may have more stringent fastening schedules such as the gable ends or the small sheer panel walls beside a garage door. Re the size of the nail It depends on the thickness of the sheathing being fastened, but for nominal 1/2" to 3/4" sheathing it is pretty safe to use 8p nails for most normal residential applications.
I don’t remember seeing screws mentioned in the code – staples are. To my knowledge, for residential wood frame construction, professionals only use screws on subfloor, or sometimes for the assembly of multi ply beams. DIYs will use them on anything.
So the pros are still nailing drywall, eh?
You got me thinking, so I went and looked...
Take a look at this web page: http://www.icc-es.org/reports/pdf_files/ICC-ES/esr-1472.pdf
and specifically at page 6. BTW - for screwing structural panels most people use the QuickDrive system. It looks like Simpson-Strongtie may have bought QuickDrive.
Besides Simpson QuickDrive, You can also look at Senco. You can download their code sheets - the number of fasteners required varies depending on the desired strength results... BUT - Their #8 2" screws replace #8 2.5" common nails on a 1:1 basis.
I.E they are equal for decks and shear panels, of course thicker sheets require longer fasteners.
Just for grins, I did some nail and screw testing awhile back.
This was a shear test - put a piece of OSB between two boards an pull them apart on the same plane. Do a search an you might find the original post with the load values I saw - usually the screws took at least 2x the shear load as the nails.
The first pic shows the screw holding still in the board, the 7/16" OSB let go first - this was a typical result.
The second pic shows the nail stuck in the OSB, pulled out of the frame.
The third picture shows why the discrepency - at high shear load, the softer nails bent and rounded the hole they were in, then simply slipped out of their hole. The harder screws kept their shape better, and thus were able to keep engaged with the wood longer even under extream load.
I'll checkout the Simpson and Senco web sites. Thanks.
You can't always use screws....
One note of caution:
You can't always use screws where you can use nails!
For instance Shear Walls forbid the use of screws. Screws are too brittle and break, where nails bend and absorb earthquake force better.
I'm not sure you can use them on studs, but I'm not sure about that.
This is where the screw guy/nail guy pissin' match gets going real good. If the shear wall were put together with GRK's it would be about twice as strong as with nails, but "various forces" resist admitting that.
Truth to tell, I like screws.
I just don't want to get failed on an inspection.
You also can't glue and nail a shear wall which is counter-intuitive.
Don't ask me. I'm not an engineer, I just follow the rules and do the best I can.
Yeah, I agree -- you basically do what will pass inspection, not always what you think is best. Maybe sometimes you do need to butt heads with the inspector, but not over screwing a shear wall.
For instance Shear Walls forbid the use of screws. Screws are too brittle and break, where nails bend and absorb earthquake force better.
Absolutely untrue. Again a nail/screw myth. Check out Senco's website, you can use their screws for shearwalls as well.
The only thing that matters with shear walls is the number of fasteners - more=stronger.
I was going by the ICC guide "Wood Framed Shear Wall Construction" (2004 edition) 3.4.20 "Wood scres are more brittle steel than nails and tend to break more easily under cyclic loading. This is especially true for drywall screws. Stick with nails in wood framing."
Here is the link I found: http://www.duraspin.com/screws.html they can replace 8d common nails. That's awesome, I had no idea. I appreciate your correction.
More only = strong on panel edges, not on the in the field. Upping field nailing actually makes it weaker. You have to be careful putting too many on the edges, without upping to a 3x.