# Roof Deck Attachment - Need some clarification please **URL:** \ **Category:** Florida and SUNachi Inspectors\ **Created:** [May 23, 2024, 6:27pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893 "2024-05-23T18:27:00Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![dfrantz](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dfrantz/32/181067_2.png) [@dfrantz](https://forum.nachi.org/u/dfrantz)\ **Post date:** [May 23, 2024, 6:27pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/1 "2024-05-23T18:27:00Z")
Please help me with this one. Roof Deck Attachment. Which box would be correct. Thank you in advance. ![20240502_114933](https://global.discourse-cdn.com/internachi/original/4X/1/3/d/13dd06811ea557e66ca69846fa662a14a1420530.jpeg) ---
**Author:** ![gbell](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/gbell/32/60114_2.png) [@gbell](https://forum.nachi.org/u/gbell)\ **Post date:** [May 23, 2024, 7:39pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/2 "2024-05-23T19:39:22Z")
Need the nail spacing to answer your question. ---
**Author:** ![dfrantz](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dfrantz/32/181067_2.png) [@dfrantz](https://forum.nachi.org/u/dfrantz)\ **Post date:** [May 23, 2024, 7:59pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/3 "2024-05-23T19:59:57Z")
6in OC on edges as well as the perimeter. David ---
**Author:** ![dfrantz](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dfrantz/32/181067_2.png) [@dfrantz](https://forum.nachi.org/u/dfrantz)\ **Post date:** [May 23, 2024, 8:01pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/4 "2024-05-23T20:01:01Z")
Sorry for the typo. 6in OC on perimeter as well as the field. David ---
**Author:** ![ddagostino](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ddagostino/32/60136_2.png) [@ddagostino](https://forum.nachi.org/u/ddagostino)\ **Post date:** [May 23, 2024, 9:46pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/5 "2024-05-23T21:46:37Z")
Share with the group what you think is the best answer. ---
**Author:** ![dhorton2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dhorton2/32/178593_2.png) [@dhorton2](https://forum.nachi.org/u/dhorton2)\ **Post date:** [May 23, 2024, 10:02pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/6 "2024-05-23T22:02:55Z")
> [@ddagostino](#): > > Share with the group what you think is the best answer. I was going to answer, but now I can’t… 😁 ---
**Author:** ![sfetty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfetty/32/331195_2.png) [@sfetty](https://forum.nachi.org/u/sfetty)\ **Post date:** [May 24, 2024, 1:36am UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/7 "2024-05-24T01:36:08Z")
> [@dhorton2](#): > > I was going to answer, but now I can’t… Why not …? ---
**Author:** ![dhorton2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dhorton2/32/178593_2.png) [@dhorton2](https://forum.nachi.org/u/dhorton2)\ **Post date:** [May 24, 2024, 3:07am UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/8 "2024-05-24T03:07:10Z")
> [@sfetty](#): > > Why not …? Was waiting for him to give us what he thinks is the best answer… (I’m sure he can figure it out, but he still hasnt tried) I mean, he only has 3 options, and he already told us what the spacing is… ---
**Author:** ![mroberts21](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mroberts21/32/285622_2.png) [@mroberts21](https://forum.nachi.org/u/mroberts21)\ **Post date:** [May 24, 2024, 10:36am UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/9 "2024-05-24T10:36:49Z")
> [@dhorton2](#): > > I mean, he only has 3 options, and he already told us what the spacing is… I dunno, I see seven options. I’ve not used any more than the first three though. There is always Unknown option. Actually, it’s the known unknown option F(Unknown or Unidentified). I’m still trying to figure out the difference between unknown and unidentified. I guess in the Venn diagram of the choice, unidentified is inside of unknown, but if unknown was inside of unidentified, it’d be known and therefore not unknown. ---
**Author:** ![dfrantz](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dfrantz/32/181067_2.png) [@dfrantz](https://forum.nachi.org/u/dfrantz)\ **Post date:** [May 24, 2024, 12:09pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/10 "2024-05-24T12:09:30Z")
My answer is C. The reason that I am asking is because there is a fellow inspector that is telling me that those are 6D nails, which in my opinion is incorrect. I am asking for your opinions to settle this debate once and for all. David ---
**Author:** ![mroberts21](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mroberts21/32/285622_2.png) [@mroberts21](https://forum.nachi.org/u/mroberts21)\ **Post date:** [May 24, 2024, 12:31pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/11 "2024-05-24T12:31:46Z")
If those were 6d nails, they’d be held in by roughly 1/8 of an inch of the remaining nail. They are driven through at an angle which means that the distance travelled through the sheathing is greater than the thickness of the 15/32 sheathing. More so if it’s 19/32. Meaning at least 1/2" of the nail is in the wood, more likely 5/8" of the nail. An 8d is 2-1/2 long. Subtract out 5/8", we get 1 7/8". Forgive me if I can’t read the detail, but it appears to me that you’ve got about 1-7/8" of a shiner exposed there. ---
**Author:** ![dhorton2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dhorton2/32/178593_2.png) [@dhorton2](https://forum.nachi.org/u/dhorton2)\ **Post date:** [May 24, 2024, 3:37pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/12 "2024-05-24T15:37:44Z")
> [@mroberts21](#): > > I’ve not used any more than the first three though. Picky picky… 🙂 I meant he only had 3 to choose from since he had access. A couple times a year I have to put unknown, if there is no attic access. ---
**Author:** ![dhorton2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dhorton2/32/178593_2.png) [@dhorton2](https://forum.nachi.org/u/dhorton2)\ **Post date:** [May 24, 2024, 3:42pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/13 "2024-05-24T15:42:21Z")
> [@dfrantz](#): > > a fellow inspector that is telling me that those are 6D nails, If it’s too close to tell, I will just label it as 8d. It can make a huge difference on their premium. If insurance wants to question it, they can ---
**Author:** ![ddagostino](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/ddagostino/32/60136_2.png) [@ddagostino](https://forum.nachi.org/u/ddagostino)\ **Post date:** [May 24, 2024, 3:48pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/14 "2024-05-24T15:48:29Z")
> [@mroberts21](#): > > An 8d is 2-1/2 long Not always nowadays, apparently. … Some of them are 2 3/8" ---
**Author:** ![dfrantz](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dfrantz/32/181067_2.png) [@dfrantz](https://forum.nachi.org/u/dfrantz)\ **Post date:** [May 24, 2024, 3:52pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/15 "2024-05-24T15:52:11Z")
2 1/4 inch per FBC 908.7.1.2 is minimum length allowed. 6D nails are 2 inch. This is clearly at least 1/4 inch and that is what I am basing my opinion on. David ---
**Author:** ![evandeven](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/evandeven/32/373798_2.png) [@evandeven](https://forum.nachi.org/u/evandeven)\ **Post date:** [May 24, 2024, 3:53pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/16 "2024-05-24T15:53:39Z")
I would base my answer on the fact that the nails appear to be nailed into thin air… ---
**Author:** ![dhorton2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dhorton2/32/178593_2.png) [@dhorton2](https://forum.nachi.org/u/dhorton2)\ **Post date:** [May 24, 2024, 4:21pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/17 "2024-05-24T16:21:48Z")
> [@evandeven](#): > > would base my answer on the fact that the nails appear to be nailed into thin air… Haha! Sometimes we have to search high and low for a missed nail… other times they are all over the place ---
**Author:** ![mroberts21](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mroberts21/32/285622_2.png) [@mroberts21](https://forum.nachi.org/u/mroberts21)\ **Post date:** [May 24, 2024, 7:58pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/18 "2024-05-24T19:58:49Z")
I would also add, that if a 6D was pounded through the sheathing to the point that 1-7/8 of it was protruding, it would probably have blown out the bottom and made a right mess of the sheathing. ---
**Author:** ![dhorton2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/dhorton2/32/178593_2.png) [@dhorton2](https://forum.nachi.org/u/dhorton2)\ **Post date:** [May 28, 2024, 10:36pm UTC](https://forum.nachi.org/t/roof-deck-attachment-need-some-clarification-please/242893/19 "2024-05-28T22:36:33Z")
> [@dfrantz](#): > > 2 1/4 inch per FBC 908.7.1.2 is minimum length allowed. 6D nails are 2 inch. This is clearly at least 1/4 inch and that is what I am basing my opinion on. you are correct. I forgot about that FBC requirement. It specifically states that “8d” nails be minimum 2 1/4". Although, that changed in 2020, and are now required to be 2.5". But thats for anything built after 2020… For wind mit credits, I would still use the 2 1/4" requirement. [Shingle-Roofing-Codes-Florida-Building-Code-6th-edition (baycountyfl.gov)](https://www.baycountyfl.gov/DocumentCenter/View/3297/Shingle-Roofing-Codes-Florida-Building-Code-6th-edition)