Tape/caulk over nail holes in sheathing?
jamesboris
| Posted in Green Building Techniques on
I’m detailing my 1/2″ plywood exterior sheathing as my primary air barrier. I’ll be taping all of the seams between sheets, but should I also run tape (or sealant) over the nails in the middle of each sheet?
I’ve seen this done on Zip homes often since the sheathing itself is the WRB, but my WRB will be a separate house wrap, so my only concern here is air-sealing strength/longevity.
Thanks!
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Replies
If you caulk the nails on any exposed surfaces, the caulked spots will tend to attract dirt and look crappy in short order. Paint is better.
On concealed things, like structural sheathing, the nails "self seal" in their holes since the wood, when it's pushed out of the way as the nail goes through, acts like a gasket and tightly seals around the nail. As others have said on here in the past, "a hole with a nail in it isn't a hole". You don't need to do any extra sealing in an air barrier where nails go through as long as the holes are tight and the wood hasn't split open. If you have big splits, or wiggly nails, then a bit of sealant is probably a good idea.
Bill
Thanks Bill. And yeah, I'm only referring to structural sheathing here... although I do have some gaps and countersunk screws in the fascia I need to patch and paint, which has been hard to get to look really "right" with a satin finish... thinking of springing for some Abatron WoodEpox... but I digress! Good to have that clarified about nail holes "self-sealing." Although I wonder if someone will come along and say that as the plywood dries out...
James,
I've removed, or tried to remove, a lot of old plywood sheathing. If anything the nail holes shrinking around the fasteners have made them tighter.
Red Devil OneTime Spackle is a terrific product to use to fill the nail holes on interior and exterior trim in high finish areas. You can apply it and smooth it with a knife, and it cures fast. If you really want to be OCD about it, you can sand it, and after you roll the paint, the patches/fill holes won't even show on high gloss paint. Also, it lasts forever. I've got some on exterior trim subject to sun and weather that has been on there for going on 15 years.