Roof Issue

[Koop]

Went up on the roof to wash today and found an unexpected problem. The roof is bowed upwards where the cross bracing supports are located. It appears like a delam. I have about a half dozen raised rideges running the width of the roof.

Has anyone seen this before? What's causing it?

[Skip426]

The rubber roof is bubbled above the seams in the roof plywood; where there is no material for the glue to hold it down; and the plywood seams are allowing enough humidity to seep through from the attic, to expand the degradation of the glue to allow the bubble to expand.
My last 5er, was doing this at three years old .
New glue can be injected, but due to stretching of the rubber, the material will not lay flat again. The bubbles are not a problem, unless the material is cut or wears to allow leaks.
If you measure the spacing of the bubbles, I think you'll find them at 48".

[Algoma]

The Alpine has a fiberglass roof, so none of this applies.

[Mr_D]

Originally Posted by Algoma

The Alpine has a fiberglass roof, so none of this applies.

OP's info shows it's a 2003 Alpine 40MDTS, so I think he knows what he's asking about.

[Algoma]

Originally Posted by Mr_D

OP's info shows it's a 2003 Alpine 40MDTS, so I think he knows what he's asking about.

But Skip doesn't.

[Koop]

Right Algoma, it's an Alpine Coach with a one piece fiberglass roof. I went back on the roof today to seal the hairline crack. It was much cooler today with cloudy skies, the ridges aren't nearly as pronounced. My take is the deformation was due to a flex causing the roof bows and roof to make contact, deforming the fiberglass. Thermal expansion makes it more noticeable.

I posted about it on my blog today.

[Algoma]

Luckily mine hasn't done that and I don't know enough about the roof support structure to help you much. I had assumed the solid insulation provided some support to the fiberglass between the frames and of course there is support at the A/C units and the roof vents. Is it all over or just in one place?

[Old Scout]

Ive seen this on several Alpines--some less pronounced than others--like my 03. Dont think it is much of an issue/nor much you can do about it until the fiberglass cracks all the way thru and you get a leak--but have not seen this occur.....

[Koop]

Originally Posted by Old Scout

Ive seen this on several Alpines--some less pronounced than others--like my 03. Dont think it is much of an issue/nor much you can do about it until the fiberglass cracks all the way thru and you get a leak--but have not seen this occur.....

Closer inspection confirms what you say. The crack is actually cosmetic checking of the gel coat, not a crack through the fiberglass. I sealed it just for peace of mind.

[Papa_Jim]

Originally Posted by Koop

Closer inspection confirms what you say. The crack is actually cosmetic checking of the gel coat, not a crack through the fiberglass. I sealed it just for peace of mind.

Two thoughts.

One. On my Monaco the fiberglass roof is not glued down, so thermal expansion differences in material can cause this kind of thing. Possibly your Alpine is built the same way.

Two. Eternabond tape might be an ideal permanent repair to consider to guarantee that this never leaks?

Jim

[Koop]

[Vtxbiker]

Hey Koop I have a 2008 Alpine 34FDDS and my roof has the same problem. Mine shows the bubble at the rear cap. I have noticed that the weather conditions seem to have an affect on the severity of the bubble. I have had a motor home repair technician take a look at it and he has seen it before and said that it should not be a problem. I don't like it but he checked it for leakage and said it was ok. I will keep a close eye on it.

[Koop]

Yeah Vtxbiker, I intend to keep an eye on things. I don't like it either, but it appears to be harmless. I think thermal expansion plays a role in how bad it looks. A hot sunny day looks worse than a cool cloudy one.