Gap under shower floor

[travelingjw]

I have enclosed a photo of a gap I found under our shower floor which is supported by 2 x 4's and a 2/8 sheet of Styrofoam sheeting. When taking a shower the floor flexes. I can fix this by raising the two supports so it actually supports the floor but I am wondering if there is an engineering issue I am missing. Changing the supports showed no difference in how the water drains. This is a single shower in a Whitehalk 23MRB

[FishNFarm]

Did they do that to keep the drain from freezing?

[2021JayFlight28BHS]

If it’s cold when you found this it may be from the contraction of the plastic…. And putting something in there could cause an issue when the weather warms up and the plastic expands again.

If it’s warm where you are then I’d prob shim the legs.

[norty1]

I believe I would shim them now and just monitor in warmer weather. You don't want that floor to flex. Drop the sprayer in the wrong spot and it might crack.

[PaulB12]

Originally Posted by travelingjw

I have enclosed a photo of a gap I found under our shower floor which is supported by 2 x 4's and a 2/8 sheet of Styrofoam sheeting. When taking a shower the floor flexes. I can fix this by raising the two supports so it actually supports the floor but I am wondering if there is an engineering issue I am missing. Changing the supports showed no difference in how the water drains. This is a single shower in a Whitehalk 23MRB

I have the same unit and had the same problem.
I just reinforced the entire space til I got it not to flex. Pretty cramped!!!!
Sloppy work on their part.
PaulB12

[Marcm157]

Did that HepVO come standard, or did you add it? Jayco cut the floor on my 28BHBE to accommodate the P Trap and I have thought about replacing it with one of those but I wasn't too sure it would work.

[muckinfuss]

They are standard in a lot of shower installations. They are not standard under sinks since a loose bit of something chunky could interfere with the mechanical sealing and you'd be quickly introduced to the rot of a grey water tank. Some residential plumbers use them under tub and shower installs....especially when extensive remodeling requires moving walls and then plumbing. Not all inspectors are up to speed on the 'alternative materials' section of the code so that can be a conflict. They say you don't have to put anti-freeze into a shower drain if you have one these, but I would....can't hurt.

[Marcm157]

Originally Posted by muckinfuss

They are standard in a lot of shower installations. They are not standard under sinks since a loose bit of something chunky could interfere with the mechanical sealing and you'd be quickly introduced to the rot of a grey water tank. Some residential plumbers use them under tub and shower installs....especially when extensive remodeling requires moving walls and then plumbing. Not all inspectors are up to speed on the 'alternative materials' section of the code so that can be a conflict. They say you don't have to put anti-freeze into a shower drain if you have one these, but I would....can't hurt.

I was shocked when I first got my camper and found that Jayco had simply cut a square out of the floor to accommodate the P trap. I used sheet metal to seal up the hole because it was actually exposed to the outside!. I think I will modify my plumbing and try one of these so I can better seal the floor back up!

[GABob]

I noticed that there was a bit too much flex in my shower after the first few times I took the RV out, so I had the dealer who services the unit fix it under Jayco warranty. Just careless workmanship from my perspective.