Just a quick question, this is in relation to #3 on the OIR01802 form.
If a Residential structure has 19/32" roof sheathing nailed 6" OC at the edges and 12" OC in the field attached to 24" OC engineered wood trusses with 6D common nails…does that meet the minimum requirement of 103psf listed in #3 B? How about 182psf as listed in C?
What about 6D nails with 6" OC at the edges and 6" OC in the field?
That would option “A”.
Option “C” requires 8D nails with that plywood sheathing, along with 6 inch spacing in the field.
Dom.
And you overthink the form.
Just answer the questions as written, you can see the choices/options listed. 6D are rated for some options, not rated for others.
Read the question again, fully. Then look at the options…I’ll underline them to help things along
A. Plywood/Oriented strand board (OSB) roof sheathing attached to the roof truss/rafter (spaced a maximum of 24” inches o.c.) by staples or 6d nails spaced at 6” along the edge and 12” in the field. -OR- Batten decking supporting wood shakes or wood shingles. -OR- Any system of screws, nails, adhesives, other deck fastening system or truss/rafter spacing that has an equivalent mean uplift less than that required for Options B or C below.
B. Plywood/OSB roof sheathing with a minimum thickness of 7/16”inch attached to the roof
truss/rafter (spaced a maximum of 24”inches o.c.) by 8d common nails spaced a maximum of 12” inches in the field.-OR- Any system of screws, nails, adhesives, other deck fastening system or truss/rafter spacing that is shown to have an equivalent or greater resistance than 8d nails spaced a maximum of 12 inches in the field or has a mean uplift resistance of at least 103 psf.
C. Plywood/OSB roof sheathing with a minimum thickness of 7/16”inch attached to the roof truss/rafter (spaced a maximum of 24”inches o.c.) by 8d common nails spaced a maximum of 6” inches in the field. -OR- Dimensional lumber/Tongue & Groove decking with a minimum of 2 nails per board (or 1 nail per board if each board is equal to or less than 6 inches in width). OR Any system of screws, nails, adhesives, other deck fastening system or truss/rafter spacing that is shown to have an equivalent or greater resistance than 8d common nails spaced a maximum of 6 inches in the field or has a mean uplift resistance of at least 182 psf.
6d = A
In other words, you have no idea if 6D nails in 19/32" roof deck, which by the way is only listed in B and C, meets the requirements of 103psf or 182psf. Basically, you give you client A without even making an effort to determine if it qualifies for EXACTLY what the from says which may give them a discount.
What happens when someone who actually knows what they are doing and how to correctly read the form comes behind you and the client finds out they overpaid for the last 4-5 years?
19/32" roof deck is only applicable to B and C, read the form. It states clearly “roof sheathing with a minimum thickness of 7/16”. How simple can this be?
I’ll show you the right way to interpret the form. B and C clearly allow any form of screws, nails, or adhesives as long as they meet the equivalent resistance of 8D nails OR uplift of 103/182psf as long as the roof sheathing is thicker than 7/16". I’ll underline for clarity:
As you can see, in A there is no minimum deck sizing requirement and the attachment is strictly staples or 6d nails that do not meet the uplift requirements of B and C.
B. Plywood/OSB roof sheathing with a minimum thickness of 7/16”inch attached to the roof truss/rafter (spaced a maximum of 24”inches o.c.) by 8d common nails spaced a maximum of 12” inches in the field.-OR- Any system of screws, nails, adhesives, other deck fastening system or truss/rafter spacing that is shown to have an equivalent or greater resistance than 8d nails spaced a maximum of 12 inches in the field or has a mean uplift resistance of at least 103 psf.
C. Plywood/OSB roof sheathing with a minimum thickness of 7/16”inch attached to the roof truss/rafter (spaced a maximum of 24”inches o.c.) by 8d common nails spaced a maximum of 6” inches in the field. -OR- Dimensional lumber/Tongue & Groove decking with a minimum of 2 nails per board (or 1 nail per board if each board is equal to or less than 6 inches in width). OR Any system of screws, nails, adhesives, other deck fastening system or truss/rafter spacing that is shown to have an equivalent or greater resistance than 8d common nails spaced a maximum of 6 inches in the field or has a mean uplift resistance of at least 182 psf
As you can see, the minimum requirements to qualify for B and C are 7/16" or greater thickness decking. Before you even consider the fastener, the decking requirement must be meet. That’s why I gave it to you first, and you didn’t even notice. As you can also see, any spacing is allowed as long as it meets the uplift/resistance requirements of 8d nails OR 103/182psf.
What’s your problem?
Take your games and snarky attitude somewhere else. Don’t assume you know more than everyone else just because you can cut & paste and underline.
Your logic is twisted or circular, and I have no problem submitting accurate Form 1802’s.
Dom.
It’s not about you and me, it’s about understanding the form in it’s simplest context…it’s about details and specifics that apply to performing the 1802 inspection properly. Truth be known, it might never be an issue, nothing is an issue until someone looses money or someone with a better understanding comes along behind you. The 1802 form isn’t worth the paper it’s written on. My advice to you is keep doing them, but just realize what the form actually is…a transfer of liability. Inspectors are getting better educated each and every day, we learn something new on just about every inspection. Myself included.
Have a good day
I second that.
6d’s were most likely not even code compliant for 5/8" plywood anyway…what a joke.
It’s not about the size of the nail, it’s about the minimum requirements for those attributes as listed on the form. What I’m saying is, the size of the nail isn’t really the requirement. The thickness of the decking and the uplift are what’s specific, 6d ring-shank nails have a greater uplift resistance than 8d common nails. It is my opinion that it would take an engineer to determine this, studies have been inconclusive and ranged from 52psf to 249psf when it comes to 6d nails. A lot of it had to do with the nail manufacturer.
Anyway, the information is there…and like I said, it might never be an issue.
I was waiting to see the formula to calculate. Did I miss that? I will still go with 6d = A
Apparently you don’t seem to understand the form in the simple context it is.
I had one last week with 7/16 plywood and a 5D nail. Now what? I marked other, after some q&a.
Preston has done thousands of wind mits, from my understanding. I think I will go with his answer.
That is a good question, how would one go about determining if that meet 103psf or 182 psf? My bet is it comes no where close to 182, was it ring-shank or common nails?
Just thinking out loud here, but how do you know that wasn’t a under-driven 6d? For that matter, is it ever completely accurate to determine nail size through the exposed nail at the attic when you can’t actually determine if the nail is under or over-driven? The topside isn’t exposed.
Thank you
I don’t think he understand the word “or”
It doens’t matter what the uplift resistance would be, that’s not your job. If it is a 6D nail it is marked A. The OIR is the one who dictates what rating gets what. Not picking on you, but you are over reading the form. I dont claim to know everything but I mark question 3 for what I see.
A 6D or Staples
B 8D spaced between 6-12" in field
C 8D spaced less than 6" in field
hope this helps:D
If you had proof of the uplift using another system(ie plans with engineer stamp) then you could use that.
I don’t feel picked on one bit, you gotta go with what it means to you. All I did was copy and paste exactly what the form says, I didn’t make anything up. Do you know if 6d common nails in 19/32" sheathing 6/6" or 6/12" OC spacing meets 103 or 182psf? I know I don’t, most of the research I have read ranges from 52psf to upwards of 249psf for 6d common nails 6/12" OC…it is very inconclusive. That being said, what would it take to determine that? The form lists you us as being qualified, so we should know.
Robert,
The way that I’ve always used the form is using the a=6d as Preston mentioned.
B = the first 1/2 of the paragraph 8d 6/12 zircon and shiner
C = the first 1/2 of the paragraph 8d 12/12 zircon and shiner
The second 1/2 of the paragraph (b and c) can be proved by an architect or engineer if the client chooses to pay them to prove this. I haven’t had the training to determine the PSF and I have been going to the training sessions since 2008. The architect and engineer has been trained through their degree and work experience to use the PSF.
But at a rate of $75 - $150 for a win mitigation, many architects and engineers don’t do many and make better money designing buildings. I’m assuming some architects and engineers do them and that is why it’s on the form.
Hope this helps. Or please correct me if I’m wrong. I also like to learn new things each day;-)
And the 1802 asks you that very question, do you know the answer?