How can I repair a soft roof

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jobguy

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Joined
Mar 19, 2005
Posts
11
Location
Minnesota
I have a '92 Winnebago Adventurer 454 Chevy 32 feet long. It has a fiberglass roof. I park it outside and over the year?s shoveling snow off the roof a few times each winter. The roof has gradually gotten very soft and mushy (does not leak). I no longer go on the roof for any reason. I scrape snow off from the side with a ladder. Do any of you know of information on how to rebuild this roof?  ??? I have repaired decking on a sail boat by drilling small holes in the fiberglass shell and squirting expanding foam in the void. But,,,, this would take forever on something this size.
Thanks
 
Hi and welcome to the RV Forum.? Sorry to hear about your spongy roof problem on your 1992 Winebago Adventurer.? I don't have any experience in anything along those lines but, hopefully, someone else here on the forum will jump in with some suggestions.? Good luck :)
 
It is strange that your roof got spongy yet there is no apparent leak. The wooden frame won't get soft all by itself.  I wonder if it is leaking along the edges where it is attached to the sidewalls and water is trickling down inside the walls. That might soften the cross-supports.

Is it spongy all over or just in certain spots?  I can't think of anything that would make it spongy all over either. 
 
Jobguy

Winnebago fiberglass roofs tend to have a problem along the edges.  The fiberglass is tucked into a channel and caulking is used to seal the seam.  Winnebago says to inspect and re-calk if necessary, every six months.  Like RVRoamer suggested, this would be the first place I would look for a leak.
 
I have a steel frame. I was not aware there is any wood in the roof. I will call Winnebago today to see if they have any suggestions.
Also it is spongy all over except where I never walked.
 
Well, steel does not get "spongy".  And even if you have steel  roof joists, they support either plywood with a fiberglass overlay or [more likely] a sandwich-like material consisting of a glass sheet vacuum bonded to a wood substrate.

Forgive me for saying this, but is it possible that you just weigh a lot more than you did several years back?  I know I do and the roof flexes more as a result.  An all-over sponginess just doesn't make much sense from a mechanical perspective - the entire roof structure would have to decompose at the same time and for for no apparent reason.
 
Winnebago service told me that water has gotten between the layers of the roof and it has seperated. Will cost $12,000.00 to rebuild the roof. I have worked a lot with fiberglass and foam over the years and will attempt some kind of repair myself. I think the first step is to get part of the roof up to see exactly what is happening and go from there. The coach is almost paid for. hate to sink as much into the coach as it is worth if I were to sell it and it had a good roof.
 
If indeed you do have "separation", or delamination, it could be what we had on our Pace Arrow. But, as Gary suggests, it wouldn't all go spongy at the same time. Although I hate to admit it, we had some bubbles show up in the roof over time, and I ignored the symptoms until it was too late. If your roof is constructed like the Pace was, the roof, the steel cage, wood, styrofoam, and ceiling were all pressure-bonded together. Water ingress caused the various layers to separate, and therefore the roof lost it's strength and rigidity.

I was given a couple of high quotes for getting the roof replaced, although there were very few dealers who could do the job in addition to the factory. Most shops wouldn't bid the work. One shop said they'd replace the entire roof with plywood, then later backed away from it. When we bought our new coach I gave the old one to the dealer rather than traded it (actually sold it for $1); I really didn't want to profit from what could be someone else's misfortune to buy that coach after some wholesaler had made a cosmetic fix.

You might look at Winnegabo's web site to see if they show the construction of the roof, then decide if it's something you want to tackle yourself.
 
I spoke with Winnebago customer relations and service. I will pull one of the roof vents inside the cabin which should give me a visual of the structure without cutting a hole in the exterior roof. I wish I had a large heated shop to work in.  I too do not want to pass on a bad roof to someone else. The coach is pristine except for the roof. I may end up rubber coating the roof and simply never walk on it again.
I appreciate all your help and I will post progress from time to time.
 
Good luck with the fix. Please come back and let us know what you find and what you do about it. If you decide to fix it, any chanve you could snap a few photos showing the condition of the roof before/during/after? I'm sure others will benefit from your experience.
 
Do? you have a flat roof?? If so,? look carefully and see if the weight of the roof air conditioner is causing a downward sag.? It doesn't take much of a downward bow to allow water to pool enough to get over the lip of the air conditioner pan and seep inside the roof.? This happened to me with an older Winnebago (70s vintage) and went unnoticed until I was camped during a downpour and started to get a shower inside.? ?I wound up bracing the inside of the roof upwards with a makeshift 2x4 frame until I could make a more permanent repair.? ?The same thing happened to Joe Lacey on one of his motorhomes and he wound up making a donut out of 2x4s to raise the unit above the water level and form a dam around the base.

As far as a more permanent roof repair, short of peeling off the existing fiberglass you could just lay some plywood on top of the existing roof, then fiberglass and waterproof the new surface.
 
We had a fellow on another forum last month who tore up his roof and replaced. He said it was a two day job for two people, with the second person mostly a go-for and  extra pair of hands rather than a skilled worker. His was a rubber roof, but the underlying structure is the same, with wood core sheathing.  Your biggest problem, I think, is to find a covered area to work in, though I suppose a big tarp would do for weather emergenices and overnight protection.

You might consider putting EDPM rubber on instead of fiberglass. It's probably an easier solution for a do-it-yourself job. Once you replace the spongy wood, the rubbersheet  is just glued down.

Here are some comments from the other fellow, who went by the name "txcampernrh".

Some tips that I learned:

1) Remove all the rotted wood, trying to use something questionable is not worth it.

2) Use a 3/8" plywood to replace deck, we used 1/4" but is a little to weak.

3) Make sure you use a good staple gun, not large nails etc, cover ALL staples with a good duct tape to keep from backing out during trips. This is very important according to all the experts I spoke with.

4) You must put wood putty in all knots, are holes in wood, let set up than DA sand entrie deck with 120 grit. Do not putty the cracks between boards, they need to move.

5) Once you get the EPDM rubber on the roof, roll out a few time to make sure it will cover and is going straight. The is time costly but is a must do. once you are sure it is correct, roll EPDM up so you have 2 rolls in the middle.

6) Cut  4 pices of a light paneling and cover the entire edges with duct tape, they should be 2' x4', these will be used for you knees and feet as you work the EPDM out to get it to stick. Place 2 on one side and 2 on the other, should cover the entire roof on most campers. Were just Sock feet....

7) Spread the glue on half the roof, you want a thick layer of glue, maek sure roof has been blown off good after sanding. Once glue is spread on half start in the middle and roll out a couple of feet at a time.  Use a rolled up bath towel to work the EPDM toward the sides or any of the openings, vents,A/C. You have plenty of time before the glue sets up, so do this real good, no hurry.

8) Repeat on the other end of camper, once the material is laid down you can install the drip rails and end caps, make sure you install the crown moldings before the center trim pieces. You will use Butyl tape under all drip rails and molding. Wait at least 48-hours before installing vents, A/C, Antenna etc.

The job is time consuming but definitely possible for a newbie, the estimates I got were from $4500-$5700 for a 28-30ft camper. I have less than $1000 in materials and about 80 man hours total so far, going to install A/C today and vents. 
 

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