Clipped Head Nails

[Stuart Brooks]

I had a pre-drywall inspection this AM and this is the first time I've seen clipped head nails used to form and connect load bearing structural members (not various metal brackets and straps)

In Virginia, the code in effect is the 2009 IRC with a few mods to appease contractors. No local codes to apply other than interpretation by the local AHJ. Table R602.3(1) lists nails by penny size, e.g., 16d and note (a) All nails are smooth-common, box, or deformed shank then adds average yield bending strength requirements. Nothing explicitly stated concerning the heads.

All the nails were over driven, sunk into the wood, most heads are barely visible. I have no idea the specification of the nails used with the pneumatic nailers.

Other than reporting that the nails used are unusual, in my observations and opinion, is this a reportable issue and refer the client to the AHJ for interperation?:confused:

[Jerry Peck]

Table R602.3(1) lists nails by penny size, e.g., 16d and note (a) All nails are smooth-common, box, or deformed shank then adds average yield bending strength requirements. Nothing explicitly stated concerning the heads.

There is explicitly something stated concerning the nail heads: "16d (3-1/2" X 0.135")" - that is telling you that the nail specified is a 16d box nail, and 16d box nail has a head which is 9/32" diameter (and the head is not clipped either).


is this a reportable issue and refer the client to the AHJ for interperation?:confused:

Yes, the holding power is reduced. They could probably had some more nails to reach the same holding power, but an engineer would need to do those numbers and come up with the number of clipped head nails (if they would even allow the use of clipped head nails).

[Stuart Brooks]

There is explicitly something stated concerning the nail heads: "16d (3-1/2" X 0.135")" - that is telling you that the nail specified is a 16d box nail, and 16d box nail has a head which is 9/32" diameter (and the head is not clipped either).

Yes, the holding power is reduced. They could probably had some more nails to reach the same holding power, but an engineer would need to do those numbers and come up with the number of clipped head nails (if they would even allow the use of clipped head nails).

Thanks Jerry. Where may I find nail specs that include head diameter? Everything I've found only states shank diameter and length.

[Bruce King]

http://senco.com/Documents/Tips/2.pdf

[Stuart Brooks]

http://senco.com/Documents/Tips/2.pdf

Thanks Bruce. Interesting. The installers in this case apparently didn't have time to adjust the drive depth. I advised the client to request the builder to pull some WRB and roofing to check for over driven nails in the sheathing. FRH or Clipped wont hold much when driven half-way through the OSB.

[Jerry Peck]

Where may I find nail specs that include head diameter?


Stuart,

Probably more about all different types of nails than you ever wanted to know is here: http://www.woodencrates.org/standards/FF-N-105.pdf