Roof sheathing

[wacdmc]

I just inspected my 2012 Keystone Copper Canyon 5er today and noticed one section of the plywood sheathing has bowed up significantly. It is actually pulling up on the rubber membrane where it meets the gutter.

It was very cold this winter, however, I would think the cold would not cause this.

Has anyone else seen this?

The only thing I can think is the cut small slits in the rubber membrane, screw the sheathing down and then patch the cuts.

Any suggestions on repairing?

[bsmith0404]

WOW THAT SUCKS! I would guess your plan would work as long as you know where the roof braces are (if there are any in that area, BIG IF). My concern, those sheets will sometimes bow as they dry, but I have never seen one that old bow without some type of moisture issue being part of the problem. Makes me wonder if it got water into it at some point. Look close for other damage somewhere.

[therink]

Wow. It appears the buckling is along the roof edge. If that is the case, I would probably start by removing the roof edge gutter to gain access to the edge of the roof membrane and lift it away to inspect and make needed repair. I would try that before cutting into the membrane.
Please keep us updated.

[Festus2]

I would tend to support Brent's assessment that there has been moisture/water intrusion into that section of plywood in order for that kind of bowing to take place. It's something that I can't ever recall being brought up here on the forum before. We've had bubbles, protruding screw heads and a couple of other "minor" roof issues but nothing quite like your problem.

Have you seen any evidence of leaks or water marks, soft ceiling, or discoloration in the interior ceiling adjacent to that area?

Another possible cause is that section of sheathing was never properly screwed down to the rafters/cross members in the first place and has now worked loose and is bowing upward.

One of the problems I see in trying to push it back into place and re-screw it is finding the cross member(s) in which to fasten it. You can't do this unless you cut, as you suggested, the rubber, peel it back and then you should be able to see where the original screws are. I think any cut you make could be fairly easily patched with some Eternabond tape and a healthy application of Dicor self-leveling sealant.

Another concern would be that, if there has been water penetration, has wood rot set into the ceiling cross members/rafters leaving you with nothing solid to hold your new screws?
Also, would you be able to apply enough pressure to force the bowed piece of sheathing to lie flat/flush?

Sorry, but I seem to have more questions than answers and not giving much in the way of helpful advice.

[abneynormal]

in my research the roof decking usually consist of (2 )1/8 sheets of luan glued together in staggered joints. it looks like you have a separation problem. do you have an extended warranty? if not its going to require a significant patch. im with the others in wondering if you have had water issues.

[wacdmc]

No water issues at all. No discoloration on the ceiling and no evidence anywhere of a leak. There are no breaches to the EPDM rubber where water could intrude. Also, the sheathing that is bowed is still strong enough to stand on.

I see that Keystone used staples to fasten the sheathing - pretty sad in my mind. I'm wondering if the really cold (-1) winter we had caused the wood to shrink slightly and pop the staples??

I was able to find a rafter and screw it down and also along the edge fairly easily. It didn't take too much pressure. I really hated to do it but had no choice since we are going to FL in 5 days.

I used rubber EPDM patch covered with the Dicor lap sealant. I've sealed this way before without a problem. The only remaining issue is the EPDM pulled out slightly from behind the drip edge. It's still tucked under and I recaulked with silicone.

[Festus2]

It seems that the repair went fairly smoothly and you must be pleased that there doesn't appear to be any water damage or wood rot. If you have time, posting a photo of the same area would be interesting so that we can compare "before and after.

I think you will be able to enjoy your trip to FL knowing that the roof issue has pretty much been resolved.

I would imagine that you will be keeping a pretty close eye on the roof from now on watching for anything similar to what you just experienced. Hopefully, this same problem won't re-occur.

[Unit]

I'm glad you were able to fix it. Just so you know, silicone generally doesn't adhere well to EPDM roofs. It would be a good idea to check that area once at your destination. Dicor makes a sealant designed for vertical surfaces and is a better choice than silicone.