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16D Nail diameter? IRC 602.3(1)

R

righter101

Gold Member
Joined
Dec 5, 2009
Messages
604
Hey everyone....

IRC Nailing table 602.3(1) specifies that 16D nails are 3.5" and 0.135" diameter.

I have a contractor asking if gun nails that are 16D 0.131" are ok.

When I look in the simpson guide, they are basing their fasteners on 16D commons being 0.162" and sinkers being 0.148".

For use with a simpson product, these seem like they wouldn't work, or would need eng. approval. Also, I understand that most simpson attachment work would be hand nailed, not gun nailed.

Anyone know about the smaller (0.131") gun nails and do you accept them as equal??

Thanks.
 
In the past, I have seen a 20% reduction in values when sinkers were used in place of commons. I don't know what diameters were used for the formula and the reduction was for all of the nails, not just hardware.

A difference of .004 can't matter much. What is the tolerance allowed for wire nails?
 
The smaller diameter is not a valid substitution. It does not matter whether the nail is hand nailed or gun nailed.

In many, but not all, situations the smaller nail can be accommodated if there are more nails.

Ask him to install as required per code or have an engineer provide an alternate design.
 
righter101 - I think there's a misunderstanding here...

The numbers in parenthesis in the tables are minimum gun nail sizes, not hand driven nail sizes.

If the contractor is hand driving nails, then go with the 16d where required.

If they are using nail guns, then look for the minimum length and shank as specified in the table on the packaging for the nails being used.

What a manufacturer might call a '16d' gun nail may (and often does) not mean that fastener will meet the minimum requirement of the Code.

Should the nails being used not meet the minimum in the table, then a DP will need to specify how many additional fasteners will be required for that connection.
 
Code tables show the minimum diameter for prescriptive construction, If you have engineering that shows the "gun diameters" work, then you are good to go, but just because that is the "gun nail size" does not mean it meets code prescriptive construction.
 
Most nail manufacturers' have a ESR Report, such as ESR 1539 which provides the prescriptive framing requirements for the various gun nails associated with the ESR Report. Have them provide you the ESR Report for the fastener manufacturer and it will provide you with the prescriptive requirements. Table 23 of ESR 1539 for example provides wall framing fastener requirements, Table 24 provides ceiling and roof framing, etc. Hope this helps.
 
ESR Reports,on their face, not necessarily code prescriptive construction. It sometimes requires a design professional to determine equivalencies
 
16d means anything. It could mean a 16d finish nail.

16d common is a specific length and diameter. I run into this all the time. I've had entire homes nailed with 0.099 diameter nails. More than once.

Apparently they just order "a box of 8d nails" for their coild guns and whatever shows up apparently passes muster everywhere else. Add in wind-resistance per WFCM or ASCE-7 and it's a nightmare. Most contractors now know what "I" want in "my jurisdiction". The rules, of course, are suspended outside my little world.

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ESR reports for the nails may be acceptable for sheathing attachment, but they don't work for a pre-engineered product that is tested with a specific diameter nail. You can go shorter with a nail in a Simpson product (with reduced capacity), but I have never seen a TB where Simpson accepts a smaller diameter. The only engineer I would trust to sign off on that was one employed by Simpson.
 
Evaluation reports cannot be used to justify a reduction in the factor of safety of the building.

An engineer can justify the use of smaller diameter nails if the capacity of the sheathed wall is reduced. In the case of a prescriptive design this may require the use of closer nail spacing or longer lengths of wall. Shorter nails can be used with sheathing and hardware when the necessary penetration into the receiving wood member is provided.

An inplace nail does not know whether it was hand or gun driven.
 
Mark K said:
Evaluation reports cannot be used to justify a reduction in the factor of safety of the building.An engineer can justify the use of smaller diameter nails if the capacity of the sheathed wall is reduced. In the case of a prescriptive design this may require the use of closer nail spacing or longer lengths of wall. Shorter nails can be used with sheathing and hardware when the necessary penetration into the receiving wood member is provided.

An inplace nail does not know whether it was hand or gun driven.
Click to expand...
It has been going on for so long ...... I am surprised that nobody told the engineers about nail guns......they should get out more often.

An engineer that designs a braced wall with hand driven nails is overpaid at any price....or 90 years old
 
The issue is that common nails are scarce for nail guns. They just aren't found on the shelves. Paslode makes a single type of 8d common, it's only available in bright. Similar difficulties exist with the other brands. Bostick used to have "hurriquake" nails, but the line has been discontinued. They do have nails of the proper diameter, but they have convoluted part numbers. When you're done with the shank diameter, you can start looking into the diameter of the head.

Hitachi does have a decent selection, but when is the last time you saw a box of Hitachi nails.

As far as the OP is concerned, the nails used in a Simpson product must be the appropriate diameter. You can't engineer your way into a smaller diameter nail as the hangers/ties were not tested accordingly. The Simpson manual is painfully clear as to what nail substitutions are allowed.

Tim
 
Common nails are fairly prevalent now. I'm using Makita's 450 psi nailing system now and the coils are standard in common sizes. .162 for 16d and .148 for 8d and 10d.

I also have seen a notation on several of my plans now where it says all nails in the called size can be common, box, or sinker. I have no idea where that cropped up at.

After many conversations with the local crowd and a couple of inspectors, they are using and accepting the .148 16d for common. I think I'm the only guy using .162.

Brent.
 
As an aside, There was a time where I was doing schools for the state. The gift of humanity bestowed on me was a full time state inspector. He once made me pull and replace all the framing in a section.

Each stud had an a-35 top and bottom to the plate. Every stud. I had nailed it all off with size 10 tico nails. The inspector said that since that nail was larger than the diameter of the hole in the hardware, I was therefore "modifying" it. All a-35's are to be nailed with size 8 joist hanger nails.

It was ridiculous and a good subject for another thread.

Brent.
 
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