waterproofing slide floor

Hi folks after some on-going health issues (all resolved, all well) I took a new approach to solving my leak issues. I found a young guy who works in my RV park who does minor repairs on the side, and he has caulked up many questionable places on my roof. Someone said you could help more if I posted a photo of my slide. The right corner of the slide is where it leaked before the floor was replaced. I call reach under the slide and feel the new floor, which is now wrapped in some sort of waterproofing material, but it still disturbing that I can reach it so easily, which means moisture can too.

As usual, your suggestions are appreciated. I haven't posted a photo before, so wish me luck. Oh, and there is a window in the side of the slide, but it doesn't open.