What is going on with the underbelly of this Jayco?

Toben .... take the advice you were given on the Jayco Owners Forum.

"Don't walk away from this RV, instead - RUN and never look back!
The worst thing to deal with in the RV world is any kind of water damage!"

There are plenty of other good used RVs out there.

All Rv's leak, its not a matter of if, just when. That one rings alarm bells to me.

Indicates one of two things. Either water had accumulated there and they made a cut to drain it, or they needed access to work on something and did not want to take the fabric down. It's a yellow flag for sure because it probably was for water, meaning a leak of some sort.

Just because seller mentions a repaired plumbing leak does not mean it is the truth. Could be a roof or wall leak. Like I say, it's a yellow flag.

I will add that on the leaker I had, it was wonderfully cared for, didn't smell of mold, and had no obvious soft spots, etc. And it turned out to have leaks in about 4 places! Now that I've had the hard knocks education in it, I know that you have to visually check basically every square inch of roof, sides, walls, floors, inside cabinets, under furniture, etc. Then investigate any suspicious findings. If you see suspicious caulk, go inside and thoroughly investigate downhill from that area.

Toben wrote:
I inspected it pretty good and saw no sign of mold, no soft floors, some minor things broken like handles, but overall in good shape. except for a repaired leak under the sink. I have lots of rental property and know this happens a lot so it wasn't that concerning to me.

Is the repaired sink leak located anywhere above the cut up underbelly.

Are the tank valves where the hole was cut. Might have replaced one and did a crappy (no pun intended) job of cutting the coroplast. I would look really good up there to see what's going on.

Kind of looks like an un-skilled butcher has worked on it. I wouldn't buy it.

I inspected it pretty good and saw no sign of mold, no soft floors, some minor things broken like handles, but overall in good shape. except for a repaired leak under the sink. I have lots of rental property and know this happens a lot so it wasn't that concerning to me.

Metal sided? Keep in mind many metal sided RVs the leak may not show up visibly inside. Sometimes stays within the walls and rots the wood.. Did someone tear the hole to inspect for damage? My question is why he bought it and wants to sell it so quickly. If the roof was replaced could be that it was leaking.

There are some videos on utube about RV inspections. Looking for soft wood. Check inside drawers and cupboards for soft wood or stains. Soft floors or ceiling near the walls. Loose trim molding on the outside of the RV and badly rusted screws. May not be a problem but inspect it closely.

Looks like the underbelly was flooded and was holding water. They might have cut out what you see to let it drain and to try to dry it out..

Could the fresh water tank had started to fall out at one time? Or been replaced? Though the hole doesn't look large enough for replacement.

As for the roof, may have been neglected. BUT... if I had my choice, I would have a trailer with an Al roof still. Lol I am still trying to learn everything I need to about the darn rubber roofs.