How do I repair damaged camper walls?

It sounds like the wood will have to be removed and replace, Paula.

Your best bet is to take it to an rv specialist , materials used in campers are mostly compostits, not real wood in this day and age.

We've remodeled our entire camper into a legitimate tiny house and helped others with repairs on theirs. It is really important to find the source of the problem before repairing the walls. Eternabond tape is very expensive, but it is crucial for RV roof repair. Especially emergency repair or difficult access areas

Then you can go about removing any damaged wood and mold. Spray down wood that does not need to be removed with a spray bottle containing water and a tablespoon of chlorine bleach. This kills invisible mold spores that might be hanging out in the wall cavity.

To cover the wall again, we've found that hard sided thin mdf works very well for new RV walls. It is thin, lightweight and looks like drywall once painted. Here's a link. Your friend has shared a link to a Home Depot product they think you would be interested in seeing:

Hardboard Tempered Panel (Common: 1/8 in. 4 ft. x 8 ft.; Actual: 0.115 in. x 47.7 in. x 95.7 in.)

https://www.homedepot.com/p/Hardboard-Tempered-Panel-Common-1-8-in-4-ft-x-8-ft-Actual-0-115-in-x-47-7-in-x-95-7-in-832777/202189720

Hi Paula,

I am assuming there is a leak somewhere and that will need to be found and sealed/fixed and then replace the wood that was damaged.