Dear Dave,
I purchased this Class C new in April 2024. Earlier this week I drove through and camped in heavy rain. I had water leaking in around the shower skylight. I also found water in the storage compartment drivers’ side rear under the bedroom slide out. My questions are: (1) Are these two related? (2) Should I be worried about hidden water damage? (3) What should I use and how do I reseal the roof? More rain is forecast. —Larry, 2023 Minnie Winnie WF326T
Dear Larry,
It is hard to determine if the leak around the shower skylight is also allowing water to travel down to the compartment without doing a thorough leak test. However, I think you have two separate issues, as the shower in your 26T floorplan is in the right rear corner and it would be a challenge for water to get to the other side of the unit to that compartment.
But, as I have said many times, I never say never or always when it comes to RVs. Your Minnie Winnie has tubular aluminum framework That is at the roof-to-sidewall joint and throughout the sidewall. Moisture can penetrate one area and travel through the framework and come out in a totally different location. This has been a real challenge for service centers as the visual leak inside could come from anywhere.
Check shower skylight sealant
I would suggest starting with the shower skylight and inspect the sealant around the perimeter. Here is the recommended sealant guide for your vehicle.
They recommend PN 131264-03-CHT, which is a Nu-Flex brand self-leveling silicone designed for the roof material of your rig.
The CHT is a generic listing, as the silicone comes in white and beige; so you will need to specify the color. You can find this at any Winnebago dealership. Since it is leaking, I would use a heat gun on the low setting and a plastic putty knife and remove the existing sealant and apply new. Also, visually inspect the skylight dome to make sure it is not cracked and allowing moisture to travel inside the dome.
Leak in compartment
As for the driver side compartment, it could be the seams or corners of the bin as they have a tendency to flex. They could allow a driving rain from the rear dual wheels to penetrate into the compartment. You can put a bright light into the compartment in a dark building or at night and look for light to “leak” out of a corner.
Another area that could be letting moisture in that compartment is the slide room directly above it. Check the bulb seal all around the room and the flange. If the room doesn’t seal flush with the sidewall when retracted, it could allow moisture to leak in a driving rain. This is known as slide room “creep” due to a valve not holding pressure, which is fairly common.
“Should I be worried about hidden water damage?”
It depends on the severity of the leak you see, and I would be concerned enough to visually inspect the area. Take off the interior ring of the skylight and see what the material looks like. You can also purchase a moisture meter like this one from Amazon and check the interior paneling and flooring of the slide room area.
I would also check the floor of the slide room and underneath the main floor for moisture, as well.
You might also enjoy these posts from Dave
- RV ‘Gremlins’, Part 6: The final chapter—RV water leaks
- My slide room floor is rotten from water damage. How can I fix and waterproof it?
- How do I find what’s causing the water leak in my RV?
- Floor is rotted under slideout of 2023 Grand Design. Why?
Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”
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Concerning side compartment doors…I had one once that the door flange was mounted into the sidewall and they put the mounting screws through the flange in front of the bulb seal causing water to leak through a couple of loose screws and eventually rotting the floor under the door. One cannot imagine how water can get in especially with poor craftsmanship.
Thank you for the suggestions and discussion, Dave! Thank you, too, for the moisture meter information. Have a great day and safe travels!
Tremendous assessment of leak causation, Dave and your determination that the moisture could in fact be getting into the tubing and traveling, is spot on, with the entry point at the skylight. Fix the skylight leak and maybe it mitigates the compartment moisture issue too. If not, at least you will know to investigate it further and find a second entry point.
Happy trails ✌️ 😎