# CDX Plywood Sheeting getting wet



## CMB_350 (Dec 1, 2013)

I am having a house built and the roof trusses and sheeting were just done last week. Since last week was Thanksgiving, the inspection was not able to be done until this coming week. Of course it's been raining this weekend and my newly sheeted roof is getting wet. It's 5/8" CDX. I can tell some of the pieces are bowed bit at the edges now. Only one piece near the front corner looks bad (starting to delaminate) and the rest looks okay at the moment. 

I was going to cover the roof with plastic sheeting but once it started raining I wasn't about to slip and fall off the roof. It hasn't stopped long enough for me to do anything.

So, will I be okay in the long run or should I have them replace any damaged pieces? I assume it should dry out before the 30# felt gets tacked down?

Thanks.


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## 747 (Feb 11, 2005)

if you have it covered with synthetic underlayment it can be left exposed for around 4 months without any issues. The plywood will dry. Now osb would be a different story.


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## joecaption (Nov 30, 2011)

Sure sounds like he has bare plywood on the roof.
Poor planning on someone's part, should have been papered over the same day.


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## CMB_350 (Dec 1, 2013)

joecaption said:


> Sure sounds like he has bare plywood on the roof.
> Poor planning on someone's part, should have been papered over the same day.


We have to pass sheathing inspection before it can be papered. I would have papered it myself if I didn't need the inspection. Not a single person I have talked to can believe how much rain we've gotten over the past 3 days. It's just bad luck on my part. I just came from a holiday party and my buddy in the building industry said he would've left it bare too. No one predicted this much rain. He says it should be fine. 

Since the original post, I was able to sheet a majority of the roof with 4 mil plastic. There's still a section exposed. It started raining again and I wasn't about to slip and fall off the roof. Honestly, it didn't seem that bad when I was up on the roof. A few boards had some bowing on the edges. The one board on the front edge is bad, but it's really the only one that I consider "needing replacement" at this time.


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## Gary in WA (Mar 11, 2009)

You should be fine, we get rain quite often here, real plywood will dry- OSB will not. I doubt it will delaminate in a week or so. You may find some buckling if the framers installed it without the required 1/8" gap between sheet ends/edges. The poly will keep the ply from drying and force it into the inner plys, remove it before the sun comes out and cooks it like a sauna...you did more harm than good- 
similar to this; http://www.buildingscience.com/documents/reports/resolveuid/39ab3b207d15b33f75e10c0bc7fa2493

Delaminating and buckling- similar to this; http://www.buildabetterhome.org/level_d.cfm?story=2796

http://bct.eco.umass.edu/publications/by-title/choosing-between-oriented-strandboard-and-plywood/

Gary


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## CMB_350 (Dec 1, 2013)

Gary in WA said:


> You should be fine, we get rain quite often here, real plywood will dry- OSB will not. I doubt it will delaminate in a week or so. The poly will keep the ply from drying and force it into the inner plys, remove it before the sun comes out and cooks it like a sauna...
> 
> Gary


Yea, like I said there really is only one piece that looks bad. Might have already been wavy on the end when laid down. It looks worse from the ground than being up on the roof. 

I'll get the plastic off once I know the rain will stop. It's still raining, btw...

Once the inspection is done I'll make sure it's dry and get paper on the roof. Should be later this week unless it rains all week.


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