Filling the void under shower pan

[Montana_5905]

Does anyone have any thoughts/recommendations on filling the void area under the shower pan to stiffen the shower floor significantly and eliminate any leakage at drain fittings from flexing of the unsupported pan floor? I'm considering a high density foam injection, or possible packing the entire void with some mortar. Any recommendations on filler materials from those who may have done this already?

[azstar]

Been thinking about this myself lately.

A thought that has come to my mind was to foam it with the insulation foam, or if lucky enough put styrofoam if I can find the right thickness styrofoam. I think I might shim styrofoam up to the right height.

More food for thought.

[Montana_1240]

Ours has styrofoam under the majority of the shower pan. (So did our previoous 2004 3380.)

We just make it a point not to step directly onto the drain. The drain was replaced once, when about new, due to that putty stuff breaking free and leaking. I scraped out the putty and replaced it with silicone caulk, and it's been just fine ever since.

Even with foam under it, I'd think that stepping on it would tend to translate some movement down the plumbing, and possibly loosen a joint in the basement. (That was also a problem with this one when the original drain was acting up.)

Steve

[Countryfolks]

I'm not too sure I would use foam from a can, It may prove difficult to work with if you need to get in there for repairs, ie the drain fitting on the shower floor, etc. I would tend to go with something removeable such as wood blocks or 1 x -- framing. Styrofoam may work but it crushes down sometimes and may hold moisture if any leaks develop.

Skip

[VanMan]

We had a crack in the bottom of the shower on our previous TT. I removed the shower/tub and repaired the crack by fiberglassing the bottom of the tub. When I replaced it I built up under it with styrofoam blocks purchased from Home Depot (I think it was HD). It removed every bit of the flex and the fix lasted several years and was still good when we sold it.

[TheCoachPotatoes]

I would suggest not filling the void with expanding spray foam. If you ever needed to take the plumbing apart it would be impossible. My suggestion would be to go to Home Depot and purchase a (1 1/2") flexible tail piece. The problem is, when you step on the shower drain, it is rigid, and installing this piece will allow the drain to have some flexiblity.

Al

After checking this, I realized it should have read 1 1/2" not
1 1/4" Sorry for the error!

[8.1al]

Thanks Al that's a good idea

[richfaa]

We are also thinking of supporting that void with styrofoam but not the foam..will think of something???

[dsprik]

Someone posted (this Spring?) about bracing under the shower pan. I believe they were using a wood frame. We are having the shower drain pulled at the dealership before we get there for PDI, and having them put a rubber gasket in and scraping all the plumbers putty off.

[Montana_1240]

From what's being said, it sounds like there is nothing between the bottom of the plastic shower tub and the floor of these Monties.

I find it hard to believe that anyone's received a rig without that foam under the shower pan. Mine has a couple or three pieces under the majority of the pan. So did our 3380.

Maybe it was an off day for the Goshen workers....

Or maybe we're talking about an entirely different shower model.

I agree with it being a bad idea to fill the entire thing with spray foam. I've been under there to tighten and seal that drain, and I wouldn't want to have to peel off a bunch of foam. Hard enough to turn things the way they need to go with such tight quarters already.

Good luck!

Steve