Replace roof sheathing during new construction?

[robby]

My builder's standard sheathing for the exterior walls and roof is 7/16" OSB. I paid extra to have the roof upgraded to 1/2" (actually 15/32") OSB. The former has a span rating of 24/16, and the latter has a span rating of 32/16.

The framers screwed up. They used the 1/2" OSB on the exterior walls, until they ran out, and then started using 7/16". They then used 7/16" OSB on the roof.

I just brought this all to the builder's attention. He's asking me if I want them to rip off the roof sheathing and replace it with the thicker sheathing, and I told him yes.

Is this a good idea? Will ripping off the roof sheathing and replacing it damage the roof trusses? Is it worth demanding the roof sheathing be replaced?

(I asked a related question in the Floor and Wall Framing forum, about the varying thicknesses on the exterior walls.)

[giddonah]

No, for the most part it won't damage the rafters (unless they're complete morons about it). Plus, if you wanted 1/2", then they shouldn't have been so stupid to put the other up in the first place. They better not charge you one cent for the mistake. Make sure there's no extra labor charges or material removal.

[robby]

Thanks for the reply.

(I think they've already demonstrated that they are complete morons, though.)

[grumpydasmurf]

(I think they've already demonstrated that they are complete morons, though.) hehehehe That's funny.

[robby]

My related thread on this whole saga veered off into a big discussion about roof sheathing over in the Floor and Wall Framing forum here:

http://www.construction-resource.com/forum/ftopic3090.html

Do any of you roofing experts here have anything to add?

Thanks!

[dhill]

I'll tell you, this is a tough decision. I think, bottom line, I'd make them redo with the original specs. They won't lose their materials, they can reuse most of the 7/16 somewhere else (somebody else's roof) and you'll have the peace of mind that the roof is as you specified originally. Right now, you're struggling with two issues (both created by their foul-up), the issue of the roof and the issue of worrying about it. Consider the stress that's caused you. Go back to your original plan, it's what you asked for, and then forget about it. They'll have it done in a day's time if they're working a full crew.

[robby]

For what it's worth, I called the APA – Engineered Wood Association hotline.

Of all the options, the technical support guy recommended the overlay of another layer of 7/16” OSB. He said it will add 1.4 psf, and result in a very strong roof.

The builder already said they would offset the new joints.

[dhill]

Well then, be sure they use ring shank nails on that overlay (or screws). You sure don't want it to buckle up.

[Cole]

Use screws it will make the roofers happy. :P

[workinhard]

Well then, be sure they use ring shank nails on that overlay (or screws). You sure don't want it to buckle up.

You got me curious there. I assume with the sheathing that's already on they would've used maybe 1-1/2" galvanized spiral nails? Something like that?

What's a ring shank nail. I mean how is it different?

What could buckle, where?

And how would ring shank nails or screws stop that happening?

I could learn something here, because I'm just not getting what the possible problem could be, and what those ring shanks are.

Thanks.

[Cole]

Ring Shank Nail:
http://i28.photobucket.com/albums/c249/Cole_22/ring-shank-nail.gif

[bkrahmer]

I know this is an old thread, but I couldn't resist... They won't lose their materials, they can reuse most of the 7/16 somewhere else Say What??? dhill, have you tried to get OSB off of a surface which has been attached with a nail gun? No fricking way. I sheathed part of my garage last fall and left it unprotected until I got the roof on in spring. I had to redo the entire north side (about 5 sheets), because it swelled and warped so bad. It took several hours with a circular saw, crowbar, hammer and nail puller to clean up that mess. By the time I was done, there was nothing close to reusable left.