Roof Sheathing Joins

ManCard · 07-05-2009, 12:03 PM

I'm constructing a shed and was wondering the proper way to nail the joined ends of the roof sheathing.

I'm assuming I would join the plywood on center of my 2x4 rafter.

If that's the case, I've read that you should leave a 1/8 inch gap between them for expansion. So between that and only having about 3/4 inch area for each nail, isn't that opening yourself up to splitting the 2x4 (especially for a hack like me who probably can't nail straight).

I guess my question is, for these joins, am I nailing straight down, or would I angle the nail so as to go into the side of the 2x4?

Thanks in advance.

Daniel Holzman · 07-05-2009, 12:38 PM

You are correct in that a 1-5/8" 2x4, less the 1/8" expansion gap, leaves only 3/4" for nailing. However, if you use the correct sheathing nail, and mark a line 3/8" off the edge of the sheathing, you shouldn't have a problem if you nail straight down. Even if you split the occasional 2x4, it will not be a structural problem, possibly cosmetic, but you are building a shed, not a piece of furniture, so don't sweat it. By the way, if the rafters are more than 16" oc, you are supposed to use a sheathing spacer plate at the center of the sheathing to maintain correct spacing. If you use conventional 16" oc, no such spacer is required.

ManCard · 07-05-2009, 02:14 PM

Quote:

Originally Posted by Daniel Holzman

if you use the correct sheathing nail

Would that be a 8d 2 1/2 inch nail?

Quote:

Originally Posted by Daniel Holzman

By the way, if the rafters are more than 16" oc, you are supposed to use a sheathing spacer plate at the center of the sheathing to maintain correct spacing. If you use conventional 16" oc, no such spacer is required.

Sorry for my ignorance, but do you have a link to a "sheathing spacer plate" on a product page somewhere? I'm unfamiliar with this, and I am planning 24" spacing. Also, if this plate is used, I'm assuming the 1/8" gap is no longer necessary?

Thanks for your help.

Yoyizit · 07-05-2009, 02:19 PM

There are also little "H" shaped aluminum holders to keep the sheet edges close to each other.

**Gary in WA** · 07-05-2009, 03:25 PM

Here is the clip, Yoyizit mentioned. It is to give support to the plywood or OSB sheathing for the 24" on center spacing.

http://www.strongtie.com/products/co.../pscl-psca.asp

Your sheathing should have a label stating a 1/8" gap all around, this clip will supply that. The box stores or lumberyards supply them. 6" o.c. nailing at panel edges and 12" in the field, if you don't live in a high wind area. Larger nails and closer spacing is used there. 8d nails with a deformed shank are recommended. Hot-dipped galvanized are good. If OSB, the slick side goes down towards the rafter. Be safe, G