Shower Enclosure - No Supporting "Foundation Material"

[BuilderML]

I thought I'd turn to this site for some sensible feedback. I build an ICF House in 2012-2013, I acted as the General Contractor and thought I had everything covered but recently started noticing some flex in my Aquatic Shower Enclosure not to mention the old water spot in the ceiling last night? It appears the water is going under the Drain Assembly's lip that screws down on the surface of the enclosure as I stand on the base and it flexes downward creating a gap for water to escape. Discovery - Plumber did not install any "Foundation Material" when setting the unit as required in the Aquatic Install Instructions and as verified when I removed the base trim from the adjoining wall and cut the drywall inspect, thank goodness my base trim is 7-1/2 inch high and the cuts are hidden. Because of access limitations I'm searching for a solution.

Before you go spraying foam or putting anything at all under the unit. 1st Your shower floor and brass drain should not be separating when you step on the floor and it flexes. I am not sure if you know how the drain assembly works but. You apply a nice amount of plumbers putty around the top lip of the brass drain slide it into hole and then slide up your rubber washer and then a friction washer followed by the large brass nut from underneath. Keep cranking down until you get a nice seal and the top ring is set nice against the shower pan most of the plumbers putty will have come out. wait a few and tighten the nut some more. Your 2" pipe slides inside the brass drain just past the top of the black rubber washer and you tighten down the nut from the top side using the tool provided with the drain.

Ok now with that being said. and the reason i said all that is you should have no separation from the shower floor and your drain lip even with flex. If you do have flex i would suspect that your drain was not properly tighten to the shower pan. It is very hard to get separation even with flexing of the floor. most times your pipe at the trap will flex first. So please do yourself a favor before you really make it a nightmare to work on. Some how verify your drain assembly is tight . Once you put that foam or what ever you use in your done no more room to work. I hope you get it to work right with out having to take out the shower unit. At least now you know what plumber NOT to call for when you need future work done. Good luck with your project.

 

[sriddle1]

Dave1949, I have full access under the One Piece Fiberglass Shower Enclosure going in from the side. The real issue is finding a suitable foam having a density of a minimum of 5 lbs./cubic feet. The FROTH PAK meets what I'm looking for, I've sent their technical group another question: "Can I tape a 2 foot length of 1/2 pex to the nozzle so I can get a more controlled flow or will it set-up before it reaches the end/opening". I'd attach the pex (one time use) to a doubled-up 16" X 16" zip lock freezer bag and slowly fill it up. Froth Pak expands 3X to 5X so steady as she goes would be the process. Once filled and hardened I'd pull the pex hose out. I'd have (4) of the Pex/Hose set-ups all ready before starting. The drain is approx 18 inches from the side = 36" wide. All I need to do is place 4 bags around the drain, forming a square, to add support. The bags would prevent it from sticking to the subfloor or to the underside of the enclosure in case it has to be removed in the future.

 

[sriddle1]

BuilderML,

Glad you wrote, my Plumber just left and essentially did what you suggested, step-by-step, almost like he was following your post. His first comment; "drain was not properly tighten to the shower pan". So he pulled it out, cleaned it up and really torqued-it-on tight. He said there was so much movement the lip started to create a wear mark on the shower pan. While we was first inspecting the movement he said he'd never seen a pan move with the slightest touch. It's an Aquatic Shower Enclosure, he said I reallt still needed to get something under the unit for support regardless so I'll continue but the lose drain assembly has been fixed.

 

[EddieWalker]

It's messy, but I always just mix half a sack of readi mix concrete and shove it under as far as I can, then use the end of a 2x6 to force it all in even farther. There gets to a point when you can't put any more under there.

Eddie

 

[SPIKER]

It's messy, but I always just mix half a sack of readi mix concrete and shove it under as far as I can, then use the end of a 2x6 to force it all in even farther. There gets to a point when you can't put any more under there.

Eddie

I agree with Eddy, you can also use lightweight drywall topping compound or even duro-rock 90 mixed somewhat dry and done as Eddy said. We did a LOT of homes drywall & often would have a few bags of 90 mixed with plus-3 to have something lighter in weight poured under them. That can be done using a drywall pump & hose...

Mark

 

[BuilderML]

BuilderML,

Glad you wrote, my Plumber just left and essentially did what you suggested, step-by-step, almost like he was following your post. His first comment; "drain was not properly tighten to the shower pan". So he pulled it out, cleaned it up and really torqued-it-on tight. He said there was so much movement the lip started to create a wear mark on the shower pan. While we was first inspecting the movement he said he'd never seen a pan move with the slightest touch. It's an Aquatic Shower Enclosure, he said I really still needed to get something under the unit for support regardless so I'll continue but the lose drain assembly has been fixed.

I am glad he was able to get it to work for you without having to take the shower pan out.:thumbsup: As far what to place underneath to support the base. Make sure what ever you place under you use caution while packing or setting in place. You do not want your floor to flex up if your forcing cement under with a 2x This will most likely create a soft spot in the pan floor. Remember you are just looking to support the floor not rebuild it from under with cement. Have fun.

 

[sriddle1]

EddieWalker, Thought you'd join-in on this post. Yes, your recommendation is looking more along the line of what I will do, after weighing the risk/reward the Foam Adventure is way too risky for my blood because of the uncontrolled expansion. For sure I need something that won't shrink or breakdown over time, not sure if it has to flex a bit. Many recommend USG's product called Structo-Lite, do you know of that product. The subs I've spoken with always cover the Foundation Material in plastic before setting the units, should I try to stuff/pack the mixture in a plastic bag to prevent sticking and future noise.

SPIKER, I'm not familiar with duro-rock 90, I've used Durabond 90, is that what you meant. I see SHEETROCK makes the Plus 3 Product, so you mixed them together to create your Foundation Material. Do you remember the mixture %

MLBuilder, Your insight on the loose Drain Assembly really hit the mark and your words of caution pretty much sums-up my concern about using foam, with my luck the foam would not spread evenly as it expanded upward under the pan and therefore causing heaving and unevenness and then I'm in big trouble, the Drain Assembly would never seal.... As suggested my EddieWalker and SPIKER, I'll go a more conventional route with a mixed mortar and physically shove it in there.

In Summary I need to ensure its non-shrinking, won't breakdown but I could use some guidance if it needs to have some flex. The last issue; "The Plastic Bag Approach". Should I attempt to shove it into a bag placed underneath the unit so the mix doesn't physically stick to the subfloor and bottom of the enclosure. That thought has been carried along ever since reading blogs about the possibility of future noise..... One good thing in all this, getting the real story out about using Foams to support Tubs, Shower Enclosures and Shower Pan. Dow's Technical Department really set the record straight with candid feedback of their: "Great Stuff Foam" Product Line and their more Commercial FROTH PAK Kits.

 

[EddieWalker]

I've found that when setting fiberglass tubs and showers, that in order to get the drain on, you need to be able to move the tub or shower around a little bit. It's a bear getting everything lined up and then secure. Then you attaché the tub or shower to the studs. The newer ones come with tabs that you screw through that go over the edge of the lip. I've used fender washers for years and like them a lot for the same purpose.

With your situation, the shower is already mounted and hopefully secure. It's not going anywhere, so whatever you use should be there to provide a solid base to support the weight of anybody in the shower. If it flexes, the drain will probably come loose again over time. Worse case scenario is if there is too much flex, you might get a crack somewhere.

Concrete is easy to work with and dries very solid. Mix it as dry as you can so you can push it with the end of the board. You don't want it to be soupy, but you want it wet enough so that it will fill all the voids and create a solid base from the floor to the underside of the pan.

Eddie