Ugh, found soft spot in my roof today! How hard is this to repair?

[Foothills Jim]

While working with some lap sealant on the roof I found a soft spot today. It’s got to be wood rot. I’d always figured if one had wood rot going on it would be by a penetration in the roof for the AC, vents, antenna etc. This spot is kind of by itself and the wood that surrounds it feels solid.



Yesterday I snugged up all three air conditioners to the 40-50 inch pound spec and I would guess that the bolts on each of them took 3-4 full turns to get to the required tightness. The roof seems solid between the soft spot and the rear AC but the AC appears to be the closest spot that any water could penetrate. I’ve only ran the rear AC to make sure it worked when I bought it and once again so it wouldn’t sit unused for so long. It doesn’t look like it’s ever been used much at all so not much condensation draining out of it to cause problems.

I bought the 2015 trailer used almost a year ago and when I bought it there were two small tears in the roof, one on the left edge by the ladder and the other on top a little forward of the edge tear. I patched both of those with eternabond and lap sealant. It didn’t seem like any would rot was going on under them so I don’t think they have anything to do with this newly discovered soft spot.

I’ve not researched this repair yet but I’m guessing cut out a section of roof membrane, cut out the rotted plywood and replace, cover opening with an oversized piece of new TPO then seal the whole thing up. It looks to be a good distance between supports under the plywood so I’m open to any suggestions on how to support the replacement plywood. Hopefully once I cut it open it’ll be easier to figure out. We’ve had rain every day lately and it’s not looking better anytime soon.

Hope I can figure out where the moisture that rotted the wood came from. NC had some crazy rain recently and it must have found an opening somewhere.
Anyone have any experience doing a roof repair like this? Any pointers would be appreciated.

Thanks in advance.

[gbkims]

Here's where Andrew started working on his 317's roof in his Resurrecting a Damaged 317 post.
https://www.mygrandrv.com/forum/show...l=1#post149113

[TheGuy]

What is the weight limit for the roof?

I have a 19 2600rb and my 250lb finds soft spots all over. I cannot believe that my roof is rotten, just my diet.

Sent from my SM-G892A using Tapatalk

[JCR GD]

What is the weight limit for the roof?

I have a 19 2600rb and my 250lb finds soft spots all over. I cannot believe that my roof is rotten, just my diet.

Sent from my SM-G892A using Tapatalk

I agree. I have many "soft spots" too. I believe my weight and some week spots in the OSB, not rotting.

[Calbar]

What is the weight limit for the roof?

I have a 19 2600rb and my 250lb finds soft spots all over. I cannot believe that my roof is rotten, just my diet.

Sent from my SM-G892A using Tapatalk

These are the areas between the joists. They feel spongy but not rotten. I have those on my 297RSTS as well. Thin roof decking for weight is the cause of this.

Rob

[TheGuy]

These are the areas between the joists. They feel spongy but not rotten. I have those on my 297RSTS as well. Thin roof decking for weight is the cause of this.

Rob

That's what I figured. I was just curious if anyone knew of a weight restriction.

Sent from my SM-G892A using Tapatalk

[Calbar]

That's what I figured. I was just curious if anyone knew of a weight restriction.

Sent from my SM-G892A using Tapatalk

I have not seen anything about weight restriction except on the ladder and I think that is 300 lbs if I remember correctly so in my thinking the roof should be good for that but then I have lots of margin on the ladder too.

Rob

[TheGuy]

Lol sounds good

Sent from my SM-G892A using Tapatalk

[Foothills Jim]

Sorry for the late response. Thanks for all the input. I weigh about 165 and I originally thought exactly what you guys are talking about, flexing between supports. However when I get down on my knees and check it out it is definitely a soft spot that feels like spongy rotten wood, ugh. I've been searching online for a place that sells TPO membrane in smaller sizes to use to cover a repair before I cut the existing roof membrane open. So far everything I see online are large rolls intended to reroof one's trailer. It's odd to me that the surrounding wood feels solid. Maybe water migrated from the rear AC opening and gathered in this one spot somehow, I don't know. I hope I can see where it's coming from when I cut it open. Sure would hate to repair some rotten wood without knowing how it got rotten to begin with.

[JCR GD]

Maybe you can just slice it open in such away to allow for regluing and laying it back in place then cover seams with Eterna bond tape.