Wednesday, November 29, 2023


Ask Dave: Can a water leak be fixed without a whole new roof? Is it even worth fixing?

Answers to questions about RV Repair and Maintenance from RV expert Dave Solberg, author of the “RV Handbook” and the managing editor of the RV Repair Club. This column appears Monday through Saturday in the RV Travel and RV Daily Tips newsletters. (Sign up for an email reminder for each new issue if you do not already receive one.) Today Dave discusses an RV roof leak.

Dear Dave,
Is a motorhome that has had a roof leak that softened the wall around a shower area considered trashed? Can this be fixed without replacing an entire roof on a 34-foot motorhome? I wonder if the repair shop is too quick to fail a roof and suggest replacing. This is a Winnebago in good shape. How do I know if it’s worth repairing? Where do you go if you do not trust your local RV store/repair shops to have your best interest in mind? —Sybil

Dear Sybil,
It really depends on the extent of the damage from the roof leak. Since you stated it is a Winnebago, it should have a one-piece fiberglass roof material. If it leaked down the wall and around the shower area, I don’t see how it could ruin the roof.

It could be delamination

You might have delamination in the sidewall and the floor could need to be replaced. The roof and sidewall are made with similar materials: a one piece fiberglass outer skin, Luan paneling, block foam insulation with aluminum framework embedded, and a Luan inner skin that has either wallpaper on the sidewall or padded vinyl on the ceiling.

Typically, if there is a water leak along the sidewall and floor, it comes in from the roof to sidewall joint or a window. The first step is to find the leak area and get it sealed properly. At the roof to the sidewall joint, the fiberglass wraps over the joint and tucks in the awning rail. Sometimes this can get cracked or even come out of the rail. The rail is not one continuous piece along the sidewall, so check the splice joint as this is a common area of moisture penetration.

Delamination explained

What typically happens when moisture penetrates is delamination. That is a separation of the materials that creates a bubbling or bulging of the fiberglass. Moisture penetrates and weakens the adhesive, so you can fix these areas if the damage is not too extensive. There are delamination kits available that have the correct adhesion and syringe to apply either through the top or by drilling small holes in the top side of the bubble and doing a fiberglass patch.

If it’s a large area, you probably need to pull as much of the fiberglass skin back or take off the affected area. This will allow you to see the damage and determine if the Luan is damaged and needs to be replaced. This is a major labor-consuming task. I would imagine the dealers you have talked to have decided the book value of the rig is probably less than the labor to fix at $150 per hour. Plus, most dealers are so far backed up in the service department they are only working on units from current customers.

Roof leak example

Here is a classic example of a roof that got water damage through the roof AC unit. The owner did not tighten the four spring-loaded bolts inside that sealed the gasket and it let water in and started to sag, which ran more water to it.

Eventually it soaked the roof and ruined it, not only around the opening but the entire roof. The cost for a new roof was estimated at 50 hours’ labor at $150 per hour ($7,500), plus parts, which would be another $1,500 or more. The unit was worth only $4,000!

Since you did not give a year or model, it’s impossible to tell the book value. If you want to tackle this project yourself, please supply as many photos as possible along with the model and year. Hopefully we can come up with a more cost-effective outcome.

Read more from Dave here

Dave Solberg worked at Winnebago for 15 years developing the dealer training program, as marketing manager, and conducting shows. As the owner of Passport Media Creations, Dave has developed several RV dealer training programs, the RV Safety Training program for The Recreation Vehicle Safety and Education Foundation, and the accredited RV Driving Safety program being conducted at rallies and shows around the country. Dave is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.


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Dave Solberg
Dave Solberg
Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club. He has been in the RV Industry since 1983 and conducts over 15 seminars at RV shows throughout the country.



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Nigel (@guest_146112)
2 years ago

Where does one get one of these roof repair kits for a Winnebago Class C roof as the one described? I’ve never seen such a kit, but I have some delamination bubbles (no leaks and no breaches, just an inferior job of adhesion IMO), and I’d like to address these before they progress. Thank you.

Thomas D (@guest_146098)
2 years ago

For once Dave was right .
The bolts holding down the ac should be checked occasionally. It’s a job done from inside the coach, not from the roof. Mine leaked and I did have to install a new gasket. Then you need to go on roof

Davidson Richard (@guest_146075)
2 years ago

Dave you said “ The owner did not tighten the four spring-loaded bolts inside that sealed the gasket and it let water in ”. Are we supposed to be tightening the mounting bolts in our ac units? If so, how often. I have never heard this before.

Dan (@guest_146078)
2 years ago

Makes me wonder, too. Should that be part of a maintenance routine? Looks like I have to try to check mine today. It’s not leaking now, I think, I hope.

Linda (@guest_146090)
2 years ago

A detailed routine maintenance article(s) would be very helpful.

Tommy Molnar (@guest_146094)
2 years ago

We had our first trailer for 16 years and barely, if ever, got up on the roof except to clean off the solar panels. Walked right on by the ac.

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