Roof bubbles, ripples, texture of the roof? Help school a noobie (with picture!)

[UglyViking]

Hey all, trying to familiarize myself with the ins and outs of what to look for in the used market as I explore out next option.

I have a Grand Design Momentum that I'm looking at and the seller sent me the following photo of the roof.



They don't look like bubbles, or ripples, but I'm not sure if it's the texture of the roof, or if it's that the roof wasn't properly installed. It looks sort of like someone sprayed adhesive, laid the roof down, and didn't apply any pressure. So wherever was the low spots connected, and the high spots didn't, if that makes sense.

Anyway, hopefully someone can help clarify for me and tell me if it's concerning or not. I tried to search (a lot) but couldn't find anything similar, so perhaps I'm just not using the right lingo.

[mokurt]

Not an expert but that does not look right.

[cadillac_al]

I'd say it is some kind of re-seal treatment. Luckily it isn't visible to most people.

[UglyViking]

Originally Posted by cadillac_al

I'd say it is some kind of re-seal treatment. Luckily it isn't visible to most people.

I'm not super concerned about the visual look of the thing, more just curious if it means there was an issue, or if it could become an issue, or if that just happens as part of maintenance?

It doesn't look "right", but I've got no clue.

[PNWGirl]

It looks like a newish EPDM rubber roof. They are supposed to be put on bare wood, not over an existing roof.

This looks like they either did not take the time to properly roll it out, getting out all the air bubbles along the way, or they put it on an existing rubber roof, which will fail and you will need to pull all of it off to the bare wood and start over.

You might consider getting a certified RV inspector to check this for you. It would be a whole lot less expensive than purchasing this and getting an expensive surprise.

Here is just one one company: https://nrvia.org

[UglyViking]

Originally Posted by PNWGirl

It looks like a newish EPDM rubber roof. They are supposed to be put on bare wood, not over an existing roof.

This looks like they either did not take the time to properly roll it out, getting out all the air bubbles along the way, or they put it on an existing rubber roof, which will fail and you will need to pull all of it off to the bare wood and start over.

You might consider getting a certified RV inspector to check this for you. It would be a whole lot less expensive than purchasing this and getting an expensive surprise.

Here is just one one company: https://nrvia.org

That's good information, thank you. I reached out to a local to seller inspector. I'll be interested in seeing what the cost of that inspection is. I suppose this is one of the risks of buying a used trailer. If you buy new and something goes wrong at least you know what and how it was repaired (either DIY or good service), where as used you really don't know.

[153stars]

Shouldn't be seeing all those seams every 48" or so. A membrane roof is continuous. Maybe grooves from underlayment gaps and dirt has embedded there.
Anybody else have stained lines in their roof. A product like Tropicool could have been applied wrong and caused lifting or is separating from rubber or TPO.

[PNWGirl]

Originally Posted by UglyViking

That's good information, thank you. I reached out to a local to seller inspector. I'll be interested in seeing what the cost of that inspection is. I suppose this is one of the risks of buying a used trailer. If you buy new and something goes wrong at least you know what and how it was repaired (either DIY or good service), where as used you really don't know.

You are right, there are risks in purchasing used. You seem to have good instincts though, to look at this roof and ask questions about it.

[PNWGirl]

Originally Posted by 153stars

Shouldn't be seeing all those seams every 48" or so. A membrane roof is continuous.

I agree. Should run from nose to tail as one sheet. There is 8' and 8.5' widths depending on if you have a wide body.

It is very odd that they put it on this way as it would invite leaks.

[US1]

Those 4' seams dont look so much as joints in the roof material, but the decking joints showing thru. When zoomed in, looks more like dirt or even pencil marking. IDK.
I see the PO was a 'More On, More On' Dicor believer. Its caked on really thick making a moat around the skylight. Nothing like building a swimming pool on your roof. He also went around the vent covers with the Dicor. Just trapping water and dirt inside with no means to drain. On the positive note, the sealant looks like one could simply peel it off with no troubles.

[RickNC]

Looks pretty rough. If I were to make a guess, it looks like someone put a DYI RecPro RV roof kit (Sold on Amazon) over an existing roof. Personally I would walk away from it.

[vito.a]

A Grand Design should have a TPO (Thermoplastic Polyolefin) roof. It should be smooth.
I suspect this one has been reroofed incorrectly.
I'd move on unless you want to tackle replacing the roof.

[Wellibe]

My trailer has a one piece TPO roof, and I can see faint dark lines where the plywood joints are. Not sure why, there aren't any gaps or unevenness, but it seems to attract dirt there, and the dirt doesn't come off with normal washing.

My roof also has a bit of bumpy texture under the rubber, but nothing like that photo. It's not really visible unless the roof is wet, and it probably wouldn't show up in a photo, but I can feel it when I run my hands across it.

That roof looks like somebody did a really sloppy job applying the adhesive.

Just thought I'd provide a point of comparison from a similar roof.

[Jkjavelin]

The seller didn't do himself any favors with this pic. Look at the long shadows. That is really exaggerating any little bumps or lumps. Take that pic at noon and you wouldn't see a thing.
JK