Ensolite expansion factor

[Johnny M]

Okay everyone got a small dilemma...the very flexible plastic poly panel 4x8 sheets we bought to cover our bathroom walls around the shower is probably not going to work...

I called the manufacturer today to find out the best adhesive to use to glue it to the polystyrene foam insulation that we glue to the inside of the body in the bathroom only to find out it is not recommended for use in RV's due to it expanding or contracting significantly for temperature changes more than +/- 10 degrees...

Bummer...if I proceed with it according to the manufacturer it will likely bubble up or the recommended glue will separate with temperature changes....

So if I don't use the polypanel my options are the marine headliner we are using for the rest of the Boler, or using ensolite in the bathroom...

So my question is does ensolite have similar expansion or contraction properties as does the poly panel which is recommended to leave a 1/4" between 8' lengths and 1/8' between 4' lengths for expansion? I know it has been used in fbrv's since the 70's but if it has similar properties of expansion as the poly panel then the poly panel might be okay???

I really don't want to use the marine headliner around the shower stall even though we have a shower curtain I am still concerned about water splashing out onto the headliner and soaking it and possibly inviting mildew to form...with the polypanel we can simply wipe it off and even clean it with a bleaching cleaner but what if the marine headliner gets wet?

[David Tilston]

Ensolite is not rigid. It is like a closed cell camping pad. I am sure it does shrink and expand some, but the flexibility keeps it from pulling away from the wall. That said, the upper corners of a Trillium are notorious for separating from the wall.

[Johnny M]

Originally Posted by David Tilston

Ensolite is not rigid. It is like a closed cell camping pad. I am sure it does shrink and expand some, but the flexibility keeps it from pulling away from the wall. That said, the upper corners of a Trillium are notorious for separating from the wall.

That is exactly what we are trying to avoid which is why we chose the plastic panel. I never thought it would expand enough to be an issue but manufacturer said it will expand and contract alot causing any glue bond to release and come down or buckle...I am confident that the headliner will stay up but if it gets wet will it cause mildew problems or will it dry out and not be an issue or should I put ensolite in there?

Thanks for the reply!

[redbarron55]

The plastic will expand and contract, but then so will the fiberglass shell. The difference could be the foam insulation that would keep the sheets of FRP and fiber glass shell at different temperatures.
I used it to line the bathroom area of my Scamp rebuild. I guess that time will tell how well it will work. Of course while I used glue to bond it yo a thin plywood panel bent to fit the curve of the wall in front and glued directly to the plywood on the sides and back and not foam perhaps this will make some difference.





There is "some" space for the panels to work, but not much.

[Johnny M]

Yes I have been watching your builds and I really like how you did your bathroom...is the stuff you used extremely flexible? Some FRP is very rigid and doesn't bend well, the stuff I got is almost as flexible as ensolite, but does get noticeable stiffer now that is getting colder here in Georgia. I haven't installed any of it yet except on the inside of my door where it is screwed to the metal frame I made for the door and I haven't had any problems with it yet so after considering how yours turned out I am thinking of going ahead and using it, worst case is I have to re-glue it or go to something else...I really did not want to use the marine headliner in the bath in case it did get wet even though we do have a shower curtain to go 360 degrees around the shower a little water is still likely splash out....

Also did you make your own shower pan? Very pro looking job

[stevebaz]

I figure the Factory used Ensolite for its ability to expand and contract with the shell. Now what happens when you line the Ensolite on the other side with your sheet goods you now have a locked in differential of expansion on both side of the Ensolite. The inner panel and the outer shell will be at different rates of expansion with the Ensolite as the insulation medium. So which will de-bond first is a crapshoot. In a perfect world both sides would stay bonded and the core of the Ensolite will go with the flow until it fatigue fails. Best would be to free float the shower structure from the Ensolite but it doesn't sound like your liner material is self supporting. You could bond your liner material to a piece of light weight plywood or Masonite so it is self supporting. The key is whatever you bond it to needs to stay at the same temperature as your liner.

[redbarron55]

I bonded the FRP to a thin plywood sheet for the curved front This plywood was attached the bottom with glue to the wooden floor and the stringer that was fiberglassed to the shell. I cut this curved plywood so that the mating surface was parallel with the floor joint and matched the tangent of the curve formed by the plywood. This was glued ans screwed with flathead screws so that the plastic could be glued to the ply.
The curve is complex in the upper left side and is kinda complex and kinda flat wrap.
The panels are held at the top with the window and tough as nails cement from a caulking gun.
There may be problems at the seams, but they are sealed with that dreaded sealant (white) to match the walls. The most important thing is to keep the water on the correct side.
My problem now is finishing the wall behind the toilet where the linen closet (top) and the Poopy Reel (bottom) are located. I guess I will just start working on it and it will somehow work out.





And just for giggles here is a shot of the strip of LEDs for general lighting. The same are under tge cabinet over the cabinet ans sink.