# Roofing nail length



## HN2018 (Oct 24, 2018)

Hi,

I am in SF Bayarea and re-roofing my home in sections at a time.
I installed 15/32 radiant barrier over skip sheating.

I am putting on Certainteed Landmark or Landmark Pro shingles.

Would 1" galvanized nails be to code?  From what I have read, it is since it will penetrate my 15/32  osb decking.

A roofer suggests I use 1 1/4 nails so that they don't back out.  I would prefer to have as short of nails sticking through on the attic side.

What nail length would you suggest for 15/32 osb decking?

Thank you in advance for your help.


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## mtlogcabin (Oct 24, 2018)

R905.2.5 Fasteners.
Fasteners for asphalt shingles shall be galvanized steel, stainless steel, aluminum or copper roofing nails, minimum 12 gage [0.105 inch (3 mm)] shank with a minimum 3/8-inch-diameter (10 mm) head, ASTM F 1667,



HN2018 said:


> I installed 15/32 radiant barrier over skip sheating.





HN2018 said:


> it is since it will penetrate my 15/32 osb decking


. Where the roof sheathing is less than 3/4 inch (19 mm) thick, the fasteners shall penetrate through the sheathing. Fasteners shall comply with ASTM F 1667.
I am confused on what your roof assembly consist off


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## HN2018 (Oct 24, 2018)

Thanks for replying.

I am not sure what roof assembly means exactly.

The current roof is asphalt shingles on top of wood shingle/shake.  There is 1 x 4 skip sheating.  I installed 15/32 osb on top of this.  The home is stick framing.

Would you suggest 1" or 1 1/4" roofing nails?


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## mtlogcabin (Oct 24, 2018)

You should have removed all of the old roofing before adding the OSB

R907.3 Recovering versus replacement.
New roof coverings shall not be installed without first removing all existing layers of roof coverings where any of the following conditions exist:

1.    Where the existing roof or roof covering is water-soaked or has deteriorated to the point that the existing roof or roof covering is not adequate as a base for additional roofing.

2.    Where the existing roof covering is wood shake, slate, clay, cement or asbestos-cement tile.

3.    Where the existing roof has two or more applications of any type of roof covering.


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## HN2018 (Oct 24, 2018)

Sorry, I forgot to mention that I did remove the old roofing materials first.  Then installed the osb.

My question is about the nail length: Would you suggest 1" or 1 1/4" roofing nails?

Thanks.


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## fatboy (Oct 24, 2018)

R905.2.5 Fasteners. Fasteners for asphalt shingles shall
be galvanized steel, stainless steel, aluminum or copper
roofing nails, minimum 12-gage [0.105 inch (3 mm)]
shank with a minimum 3/8-inch-diameter (9.5 mm) head,
complying with ASTM F1667,_* of a length to penetrate
through the roofing materials and not less than 3/4 inch
(19.1 mm) into the roof sheathing. Where the roof sheathing
is less than 3/4 inch (19.1 mm) thick, the fasteners shall
penetrate through the sheathing.*_


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## HN2018 (Oct 24, 2018)

Ok,  you guys are good teachers.  You quoted R905.2.5 twice for me now.  So I will answer my own question. Both length of roofing nails are to code.

Thanks.


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## Pcinspector1 (Oct 24, 2018)

HN2018 said:


> The current roof is asphalt shingles on top of wood shingle/shake. There is 1 x 4 skip sheating. I installed 15/32 osb on top of this.



What was the length of nail used to nail the OSB to the skip sheeting? Hope it's long enough?


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## fatboy (Oct 24, 2018)

HN2018 said:


> Ok,  you guys are good teachers.  You quoted R905.2.5 twice for me now.  So I will answer my own question. Both length of roofing nails are to code.
> 
> Thanks.



So happy to help out..........


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## HN2018 (Oct 24, 2018)

Pcinspector1 said:


> What was the length of nail used to nail the OSB to the skip sheeting? Hope it's long enough?


I renailed the skip sheating with 8D nails and used 3" .131 nails for osb if using a framing gun and 12D sinkers for hand nailing.

Is that good?  Suggestions?

Thanks.


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## ICE (Oct 24, 2018)

For anyone that might be thinking about doing the same thing with radiant barrier......understand that radiant barrier ceases to function when there is no airspace beneath it.  So the space without the 1x sheathing has value and the radiant barrier in contact with the sheathing does not.  I have also been informed that osb radiant barrier in contact with wood can create a condensation issue....probably more so when placed over existing plywood sheathing than over skip sheathing.

As a footnote: If you are serious about getting a benefit from radiant barrier, don’t forget the gables.


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## HN2018 (Oct 25, 2018)

@ICE 
I don't understand your suggestion "don't forget the gables".  Could you be more specific?

BTW, my home has a roof but there are two gable dormers.

Thanks.


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