Carpet has mushrooms growing along wall

You got black mold deadly stuff. Using an approved face mask, remove the carpet, probsbly the flooring too. Good luck. Seems dealer did a pee poor job of fixing your issues.

I think I,d check with the insurer first.

and use a biocide on anything you leave in place. Do not try to reuse the carpet.
Contact your insurance company and see if they might cover it.

First off, I don't like carpeting in any RV. Carpeting is a nice way to cut assembly cost. Much preferred is hard surface flooring. You can add throw rugs if needed.

Secondly, black mold is deadly. Time to remove ALL the carpeting with a NOSH approved face mask or supplied air resperator, you don't want to breath in any mold spores.

If it's happening along the wall / floor juncture, you have water intrusion in that wall and most likely soaked insulation and rotting framework and that is a major, major job to remediate.

I have to ask, have you ever checked your seals and caulk for failure areas? I bet not. You must at least bi-yearly, check all the seals and caulk seams for failure and reseal and re-caulk as necessary or...you wind up with what you now have.

My personal view is, the dealer fixed the issue but follow up seam and caulk maintenence wasn't done by the owner.

I've seen brand new, on the lot units with water issues pending. Just pulling a unit from the factory to a dealer can compromise the seals.

Maintenance is an important (but overlooked) aspect of RV ownership. Now, you get to pay the price for your lack of care.

Interestingly, you can purchase Eternabond and Dicor at any home improvement store, Sikaflex too, but you have to use it to do any good.

If it was my unit, I'd patch it up and trade it in. Because you are looking at not only an expensive job (remediation), but a long time duration as well.

No way to candy coat the obvious.

I assumed no insurer would cover any of this. We don't have much confidence in the dealers or the sellers. Or the insurance. We do have a Good Sams Extended Warranty but nobody has ever covered anything so I doubt this is any different. I did use a mask and wore gloves when I cleaned it up. I have a fan on the area now ventilating it.

Husband has gone onto the roof every 4-6 months and been very good about caulking, checking for leaks and doing sealing maintenance. Its our 3rd rig, he has done an exemplary job of taking care of it and watching the roof. We checked for water leaks frequently and we ventilated it all summer. It was kept covered all winter too. Now I feel awful. Can we fix this and remove the bad areas of flooring and carpet and at least use our rig for the rest of our camping plans this summer.

Water just don't come in via the roof. Every intrusion in the outside walls are a potential leak, from an outside light, to an outside shower to a HWH insert to a luggage door, they all are potential leak points.

What I would do is make an appointment with a local CW or other facility that has is a Seal Tite authorized shop and have a Seal Tite test run on the unit. That will tell you exactly where the intrusion issue is and I'd do that before anything else. It's the only foolproof way to determine where the water is getting in, because it is getting in somewhere, You may be surprised.

It is possible to do a positive pressure test (also called a blower door test) yourself but I'm not going to get into it here. You might try using the 'search' box at the top of the page and type in 'leak testing.

Can you use the unit? Youe level of personal safety isn't mine. In my case I would not but, I'm not you and you aren't me.

Well thank you for the advice. I do appreciate all the input and advice I can get, when my husband gets home from work we will do what we can. I did put a call in to our insurance lady. I treated the area. I am a Chemist and I know 3 non toxic ways to kill black mold are 3% Hydrogen Peroxide, Tea Tree Oil and Vinegar. I have all 3 here. I will have him take out the carpet while wearing a mask. I will treat the area underneath as best I can. And ventilate. And search for a leak. This sounds like a monumental task to me and we have a trip planned this weekend. If we get the carpet out and treat the wood or subfloor underneath I guess thats a start. I am not using chemicals in the RV, they can be worse then mold. This appeared to be a fungus for certain though. And breathing any of them is deadly in a closed space. I am just sick to my stomach thinking about this. Its the newest RV we have ever had. I want my old Winnebago back. Should we even bother calling the place we purchased it from, they were the ones who replaced the wall on that side last fall.

To the OP
Black mold is deadly! Do not use or even enter the RV without an approved face mask or ventalator. A paper mask won't do any good.
If you inhale black mold it will grow in your lungs. Get an inspection done to determine if you have have black mold. If it is indeed black mold you have a very expensive repair. If your insurance will cover the RV they may total it. Yes it's that serious!

friend had mold his insurer covered a very large repair bill. never hurts to find out. and I,d see if there was any warrenty from the first fix. good luck.