2016 Montana 3710FL front living room slide out bottom

[RVRoadramblers]

Hey all, I am hoping someone here can help me out with this.

Our 2016 3710FL Montana has the two slideouts up front for the living room. The weird thing about it is that each of the slides have different material that make up the slide bottom. The slightly smaller of the two next to the front door has a textured brown or black solid plastic sheeting as the exterior floor face. The opposite side slide out has a cream colored sheet of plastic that actually matches the rest of the trailer.
So, 1st question is why the difference?

Next, we very recently had like 40days of rain and began noticing that the carpet was getting wet and staying wet so we pulled it up to reveal wet plywood along all three outer edges of the slide. We immediately began operation dry-out with fans and whatnot. Also noticed on the exterior that there were some obvious seams where the caulking had separated, which I'm positive we're the culprate.
Thankfully, for the most part I don't believe that the water damage resulted in rot or mold but, as we are putting this slide back together, I noticed two things that are concerning me. One is that Ive noticed that the plywood in the leaking slide seems to have a slight bow or sagging toward the center of it and wonder if this is something that I should consider how to straighten out? The slide is currently in the extended position.
Also, in looking closer than I ever have, I see that, from the That interior that thin cream colored plastic piece is visible just under where the carpet rolls over the edge. I'm curious what product that sheet is actually made of? Is it normal for it to also sag ( more so than and independent from the plywood subfloor) and the last element is that I also noticed that the rollers that support the slideout have sorta crushed a spot where they are when the slide is fully closed, something I can only guess happened while in transit.
I don't know if I need to consider replacing the full sheet, of plastic, or is there another option that I could consider that would alleviate that problem?
We live full-time in this thing and so find it very difficult thinking about putting the rig into a shop somewhere. I don't even know if that is a feasible option for us.

Has anyone ever repaired/replaced the wood, plastic sheeting or rollers on one of these?

I have added pictures of the holes made by the rollers for reference.

Thanks in advance for any input.

[Mikendebbie]

Both of those front slides should be Schwintek mechanism slides. The standard bottom material is black UHMW plastic sheeting that is glued to the underside of the plywood floor. When the glue gives out - the plastic sheeting will sag a bit.

Just curious if you are the original owner? The cream colored sheet with the hole in it looks to be filon (fiberglass sheet). It is the same material they put under the front nose, and it wraps down around the front bay doors. Maybe it was close to the end of a shift and the boys in the factory ran out of UHMW sheets, and the foreman thought it would be ok to substitute filon for the UHWM so they could button up the slide box before quitting time. If you are not the original owner - then I think the previous owner had leaks in that slide, or the OEM UHWM was damaged, and the dealership replaced the sheeting with filon. I am no expert but I don’t think filon has the same compressive strength and puncture resistance as UHWM. If it was as good as UHWM we would see more slide bottoms covered with filon.

You need to figure out what caused the puncture…maybe a screw head backed out enough to hang up on the filon. You could patch the hole with standard fiberglass patch kit - but the screw head or whatever will poke another hole thru the patch.

Do a google search for a YouTube video “AZ RV Expert replacing rotten slideout floor” (screen shot below). The video will help you understand the components of your slide floor, how the UHWM sheet is glued to the plywood floor, and the caulking to stop leaks. The slide in the video is a hydraulic slide - not a Schwintek but that is a small difference for your issue.

The leaks causing the wet floor are a separate issue from the filon soffit hole. You need to clean and reseal/re-caulk the bottom corner aluminum trim, as well as the window frame perimeter. If you still get wet floors, you need to remove the window frames and reset them in new putty on all sides, then caulk the window frame all around.

[Lkasper12]

I also have this unit and have the same materials on each of the slides. The passenger side has the black plastic underpayment while the driver side has the cream filon. The filon sheet is separated from the flooring and sags inside the unit when the slide is retracted.

The slide mechanism is a BAL Accu-slide cable system for both the forward slides.

Pam&Len
2016 Keystone Montana 3710FL
2019 Silverado 3500HD LTZ