Little bumps in the bathroom wall

rhb50 · 03-04-2020, 11:57 AM

Hi,

Hope someone can recognize (see pictures in link) what these bumps in the wall in my 2015 Itasca 27N bathroom might be. They are hard bumps, not soft. There are many more small ones near the ceiling but bigger bumps about sink counter height. If you click on each picture you can see them better, especially the ones higher up.

Thanks

https://photos.app.goo.gl/UT8MPFW8kV5mTGse8

Morich · 03-04-2020, 02:27 PM

Not seen those in that number before so it brings some questions. Is this a new RV and is it something that is growing or just now noticed?
Theory, without anything to back it?
Maybe just a poor prep job that left a bunch of sawdust before the covering was added? Not a metal wall where corrosion would build if there is water?

I would want to know enough to make a small damaged place on the wall. I would pick an out of the way spot, use a sharp knife to cut the covering and find out what is inside the bump! Small 1/8 inch hole to be hidden with a dab of spackle or toothpaste, perhaps. Toothpaste does make pretty quick and easy filler for hiding things like nail holes, if the wall is the right color.
Not wanting to go to lots of trouble as you can see, but I would be wondering.

rhb50 · 03-04-2020, 02:49 PM

Not new, 2015. Just noticed the bumps.

powercat_ras · 03-04-2020, 03:05 PM

The wall covering is similar to vinyl wallpaper, glued to 3/16" 3-ply interior plywood. Not happening in mine. I would call Winnebago BEFORE making any disturbance to them and see if they have any silent warranties for the problem. Only related thing I have on mine is the wall covering shifts slightly and gets slight wrinkles around some window frames where the window has moved slightly over time.

My build date was December, 2014.

Bill Forbush · 03-08-2020, 08:30 PM

Had exactly the same thing in our 2015 Jayco 5th Wheel. A dealer told us it was indicative of a leak/water damage. I never did find any sign of water and later traded it in on our Winnebago. Good luck!

JoeSR · 03-11-2020, 08:25 AM

As Bill Forbush wrote, that is water damage. I have the same problem on my motorhome in at least two spots.

My entry door was leaking where Winnebago joined two pieces of filon siding together and hid the joint behind a piece of molding. The joint was suppose to be sealed with some flexible goop, but the factory did not cover the joint completely.

My second spot may have been caused by a leak at the roof to side wall joint. Make sure you "roof cove maintenance" is up to date.

My second spot could also have been caused by a leaky window seal. I have made a temporary repair here. This spring I will remove the window and do the repair correctly.

Just some ideas of what could be the cause.

Morich · 03-11-2020, 08:51 AM

I agree that leaks and water can cause weird looking things in the wall covering but looking at the location and amount of bumps way down the wall at the vanity height, I do not feel like it is water leaking in as it is in a bathroom wall, not an exterior wall and not very likely to have a joint of any type overhead as well as that much water to penetrate that far down over such a large area, just seems out if it was not a total firehose.
Just one of those little mysteries we may read about and never hear more if the OP doe not report back when they find more info.

Delco Bobby · 03-11-2020, 04:46 PM

Quote:

Originally Posted by Bill Forbush

Had exactly the same thing in our 2015 Jayco 5th Wheel. A dealer told us it was indicative of a leak/water damage. I never did find any sign of water and later traded it in on our Winnebago. Good luck!

I agree. It looks like some water damage. You may have an occasional leak. Depends on rain and wind direction and slope of RV.

powercat_ras · 03-11-2020, 05:20 PM

The way the Vista 27N roof system is built about the only places you could get water that would effect the inside side of the outside wall would be thru the skylight to roof seal or perhaps the toilet vent stack, and that's quite far away from the outside wall so that's a low chance. There's also a grey tank vent that goes up the inside wall between the bathroom and the hall very near the return air vent location.

You might go up on the roof and inspect around the skylight and roof vents. On my 2015 27N, the lap sealant was under-applied at the factory on the wall side of the skylight and I had a small leak that I caught early before it did any damage. It was also detectable by inspecting the skylight screws inside the bathroom, the skylight screws are just zinc plated steel and quickly start to corrode if any moisture is entering around the skylight.

Good luck.

charliedias · 03-11-2020, 05:52 PM

I bought a 2017 NEW Spirit 26A in Nov 2017. Cyber Monday, great buy on a new RV. Parked it, Bagged it.

2018: Opened it for the spring. Noticed the bumps.

Estimated $4,000-6,000 to replace panels if Warranty doesn’t cover it. Warranty covered it. Big job, bring it in at the end of the 2018 season. Ok fine. They had it for months.

Hard bumps are Luann sawdust behind the vinyl. Why are they there ? Vibration, Workmanship, Loosened by water or dampness ? Pick one.

They had it until mid winter & winterized it. No more bumps. Snow on ground, parked it. No bag.

Spring 2019: Take in for FREE deWinterize. Moved 2 feet, my back is soaked. Top bunk FILLED with water.
They found a seal problem. Repaired under warranty.
Why? Bad repair ?

RV didn’t leak BEFORE they fixed the panels.

Dealer had it until SEPT 2019. RV Year & Season was LOST. Walls are still nice though. No Bumps.

Devaluation for 1 whole unused year of 2019 ? Unknown.

danhannah · 03-11-2020, 08:03 PM

These bumps are suspiciously near the black water rinse riser and vacuum breaker under the 27N bathroom sink.

Pressurize the black water tank rinse, then look under the sink with a flashlight for leaks! You will have to lie on your back and look way up into the sink cabinet to see if the riser is spraying water.

Best of luck!

Wyatt · 03-11-2020, 08:43 PM

Thinking too that it’s water damage. Moisture seeping behind the superficial wall treatment.
You said this is in your bathroom? Is your shower also in that same room? If so, do you keep it well ventilated during hot showers?
You can see it starts where what appears to be behind the mirror, and lessens as it goes down, another indication on water and gravity acting together as the culprit.

valsamik · 03-12-2020, 03:29 AM

I have the same bumps that became visible after my Sani-flush valve sprung a leak and shot water all over the place along the same wall area. Moisture collected more in the upper portion of the wall when I was drying it out because heat rises, so I think. Just thought I'd share my experience in case you might recently had a leak in that area that may have not been caused by roof issues.

Mike

Joette · 05-19-2020, 06:27 PM

Do you use the bathroom fan when showering? If not, it could be mold growing under the vinyl wallpaper from the steam from the shower. Bathrooms in RV's are not large enough to dissipate the moisture from showering and it settles on your walls, and causes damage like this sometimes. We learned the hard way to always use the shower fan; we even took out the loud high speed one in our 27N, and put in a three speed so we could use a slower setting, but we let it run longer than if we use it on a higher setting.