osb + rain=?

[Mikelopic]

just a quick question, how long can I leave osb,(the cheap stuff) uncovered without causing any damage to it. I plan to sheath half the roof this weekend and the other half next weekend, and then tarp it , thank you...

[Jens]

Should be fine, just make sure you have it all nailed off first.  If you can, go ahead and tarpaper it as you sheath, use the washer head nails, not staples.  Its a bit of a PITA, but much safer.  While you are at it, put up 2x4 stickers over the felt, then tarp everything.

[MountainDon]

I'd at least try to cover the sheathing with roofing felt, or whatever you choose, at the same time I did the sheathing on that half of the roof. You never know what surprises the weather may spring on you to prevent the next weeks work from happening on schedule.

I purposely left some cut offs of OSB lay about up in the mountains. After a couple rains I noticed swelling on the cut edges. Some places on the smoother side of the OSB had some of the "flakes" of wood coming loose from the surface.

One quarter of my completed gazebo roof stayed just covered in felt for several weeks after the other sides had the shingling completed. It rained many days through tat time. The felt didn't seem any worse for the rain.

[OldDog]

I have just returned from checking my tarped roof after a BIG storm.

Thank Goodness the "Katrina Roof" is still intact with only a total of a pint of water anywhere.

Bruce

[Redoverfarm]

Mike

If your project is extended for any period of time I would use "titaninum felt". It is a rolled product simuliar to plastic feed sack material in 4' wide rolls. It is installed with button nails.  It is a little more expensive than felt but it is worth the extra$$. I put it on in Nov of last year and put my metal roof on this year. The manufacturer states it is good for 1+ years.  If memory serves me correct I think it was $150 for a roll that was 10 sq.

[glenn kangiser]

About 6 months wet on the good stuff with water removed at every rain is about enough to do it in.