New Advice from BITOG on Yet Another Home Project Problem

[LoneRanger]

Okay, so this house we bought things just aren't going smooth in a few ways. We paid a master plumber to do a partial bathroom remodel. He and his assistance or apprentice removed a combo tub/shower, the type typically used in homes built within the last 15 or so yrs. It was replaced with a shower only alcove of dimensions 60 x 32 x 80, and a semi frameless bypass sliding shower door. It was a turn-key job with them subbing out the drywall work and them doing all the removal of old and install of new. They put in the following alcove, Aker by Maax KDS 3060 https://maax.com/en/product/kds-3060_145036/ It's a left seat right drain config. As soon as we used it, there was a floor flexing issue right where you stand while showering, about an area of 16" lengthwise. Up around the drain and towards the back of the floor pan it is firm and doesn't flex. Neither of us are overweight, she's about 150 I'm about 200. The middle of the flex zone you can actually take your hand and press down and feel it move maybe 1/8" until it contacts the subfloor. Clearly, it's an installation issue. Again, pro install, not DIY. Notified them of the situation and they came out, checked it, and said they'd come back the next day and could either shim it from crawl space or use an expanding foam product like Dupont Great Stuff Door and Window gap sealer to create a rigid substrate in the area that needs support. They said it has "feet" on underside of the floor pan and the center ones must be lacking a bit from resting on the subfloor. After they came back and did the specified procedure, lo and behold the next morning it's not much different, still flexing in the same place under foot when showering. This evening after work I went into the crawl space to see if they did in fact foam it and they did, There is about a 8" diameter hole in subfloor where the drain and pipe come through, and there is dried/cured foam all along the back radius of the hole so clearly they attempted to insert expanding foam but likely just didn't get enough of it far enough back to fill the problem area completely. My first question: Will this type of insulating foam like Great Stuff even be rigid enough to serve as an effective substrate for purpose of stabilizing the fiberglass shower floor? Second question, what do you think about using a drill with maybe a 1' or so diameter hole saw bit to make a few entry points in the subfloor under the problem area to insert and spray foam where they weren't able to get it to from the farther forward drain pipe access? Subfloor looks to be about a 3/4" thickness or better OSB. There aren't many other choices except the Nuclear Option which would be demanding a tear-out and re-do, and 1. I'm not sure they'll do it, and 2. We don't really want the mess. They put this shower alcove in before we moved in, but we're moved in now and it would be a major annoyance.

 

[spasm3]

I like the look of that unit! I'd call Maax and get their take on the problem, product problem or install problem. Says its only available in the west

 

[dbias]

No foam will help this situation. Now it's just in the way of any real resolution of the problem.

 

[Kjmack]

In that situation there should be a light weight concrete type product , sorry I can't remember the name . For uneven floors like you had . The plumber mixes it up and pours it in place before setting the shower , tub or whatever . Set the fixture then settle it in place . Makes sure it's level then let it set up . Sounds like they rushed the job . Sorry for your issues .

 

[spasm3]

Originally Posted by Kjmack

In that situation there should be a light weight concrete type product , sorry I can't remember the name . For uneven floors like you had . The plumber mixes it up and pours it in place before setting the shower , tub or whatever . Set the fixture then settle it in place . Makes sure it's level then let it set up . Sounds like they rushed the job . Sorry for your issues .

Do you mean Durham's rockhard water putty?

 

[Kjmack]

Originally Posted by spasm3

Originally Posted by Kjmack

In that situation there should be a light weight concrete type product , sorry I can't remember the name . For uneven floors like you had . The plumber mixes it up and pours it in place before setting the shower , tub or whatever . Set the fixture then settle it in place . Makes sure it's level then let it set up . Sounds like they rushed the job . Sorry for your issues .

Do you mean Durham's rockhard water putty?

Sorry been so long I can't remember

 

[zrxkawboy]

^^^Sounds like floor leveling compound...I'm sure there are different brand names. Unfortunately, it's too late for that. BTW, I agree that the expanding foam would not be a solid enough base for this purpose.

 

[CT8]

Originally Posted by Kjmack

In that situation there should be a light weight concrete type product , sorry I can't remember the name . For uneven floors like you had . The plumber mixes it up and pours it in place before setting the shower , tub or whatever . Set the fixture then settle it in place . Makes sure it's level then let it set up . Sounds like they rushed the job . Sorry for your issues .

This is the proper installation method.

 

[JLTD]

Originally Posted by CT8

Originally Posted by Kjmack

In that situation there should be a light weight concrete type product , sorry I can't remember the name . For uneven floors like you had . The plumber mixes it up and pours it in place before setting the shower , tub or whatever . Set the fixture then settle it in place . Makes sure it's level then let it set up . Sounds like they rushed the job . Sorry for your issues .

This is the proper installation method.

Agreed....and it should have been done initially. Had one like this, it cracked and leaked within a couple months. It's time for a pull-it-out redo.

 

[JC1]

How big is the area that flexes? Could you get under Neath in the crawl space and cut out some of the OSB or plywood and then use a rigid foam piece which would be rectangular that would be inserted in between joists and then turned 90 degrees to span over the joists and stop most of the flexing? Then you would need to cut new OSB and. Then put blocking with 2*4 in between the joists to firm it up.

 

[LoneRanger]

So it sounds like they bungled the install. Nice. Small company basically two guys, referred to them by the realtor we bought the house through. Awesome.

 

[LoneRanger]

Originally Posted by dbias

No foam will help this situation. Now it's just in the way of any real resolution of the problem.

Not sure you're correct. This foam product states it is specifically for use as a substrate for setting bath/shower tubs: http://www.multitechproducts.com/polyurethane-injection-pour-foam-kit-a-b-components-5-lb-density/ Found someone else with exact same problem, foam considered as option: https://www.johnbridge.com/vbulletin/showthread.php?t=52748

 

[WyrTwister]

Originally Posted by Kjmack

In that situation there should be a light weight concrete type product , sorry I can't remember the name . For uneven floors like you had . The plumber mixes it up and pours it in place before setting the shower , tub or whatever . Set the fixture then settle it in place . Makes sure it's level then let it set up . Sounds like they rushed the job . Sorry for your issues .

Quick Set ?

 

[BMWTurboDzl]

Originally Posted by JC1

How big is the area that flexes? Could you get under Neath in the crawl space and cut out some of the OSB or plywood and then use a rigid foam piece which would be rectangular that would be inserted in between joists and then turned 90 degrees to span over the joists and stop most of the flexing? Then you would need to cut new OSB and. Then put blocking with 2*4 in between the joists to firm it up.

^^^This Rigid foam is dense enough to prevent flexing however I suspect that problem is that the subfloor (OSB) has too much deflection. You can tell by having someone stand in the the shower while another observes the OSB in the crawlspace. If the OSB is flexing then the rigid foam might not even been needed and it's just a matter of adding additional blocking.

 

[LoneRanger]

OSB is not flexing. You can put your hand in the area of the shower floor that's flexing and push down and feel the shower floor move slightly then contact the OSB subfloor and stop. One or more of the "feet" or ribs in that area is not in contact with the subfloor by maybe 1/8 - 1/4" It's an install error as far as I can tell. The only two options are to try some method from underneath in the crawl space to add some type of substrate and fill the entire space in the flexing zone, or the nuclear option which is a tear-out and re-do. I have doubts however, that the installers will agree to a tear out and re-do on their dime. We also truly want to avoid the hassle and mess of that.

 

[ARCOgraphite]

Mud and tile or stone. FG is so 70's. My FG tub flexes under foot in spots. Been doing so for 29 years. Year zero I was 187 lbs, year 29 I am 247 lbs

 

[ARCOgraphite]

HD Expanding foam should do it. Think of the force per unit area (sq-in) as small with the load being distributed by the floor membrane. Bore A 3/4" hole a few inches (12") from where the issue is - insert straw to the area of concern - fill as you pull the applicator straw back towards the hole. You can do it .. NO biggie. Let it cure. Be careful, the force of the expanding foam can distort large areas of plywood.

 

[BMWTurboDzl]

Originally Posted by LoneRanger

OSB is not flexing. You can put your hand in the area of the shower floor that's flexing and push down and feel the shower floor move slightly then contact the OSB subfloor and stop. One or more of the "feet" or ribs in that area is not in contact with the subfloor by maybe 1/8 - 1/4" It's an install error as far as I can tell. The only two options are to try some method from underneath in the crawl space to add some type of substrate and fill the entire space in the flexing zone, or the nuclear option which is a tear-out and re-do. I have doubts however, that the installers will agree to a tear out and re-do on their dime. We also truly want to avoid the hassle and mess of that.

Ya, they should've shimmed the feet if your subfloor is uneven. Have them add more low expansion spray foam from a different location. I hate FG showers, seems that they all eventually develop some amount of flex.

 

[JustinH]

Thats too bad, for the price of that unit could have you done the whole shower with Tile? I put those glue up shower walls in a rental property they look ok at first but never weathered for long.

 

[LoneRanger]

We didn't want tile or slate. That also would've required tearing out and replacing the entire tile floor of the bathroom with matching slate or tile to what would be used in the shower alcove. And the off-white eggshell tile floor of this bathroom is recent w/i the past few years, in excellent condition, and we like the look of it. Just wouldn't seem right busting that up. That would've turned the minor remodel (shower only) into a major remodel, again something that was not our goal whatsoever. We like the look of bright white smoooooth fiberglass and much easier to keep clean. The house I'm selling, my place which I bought as new construction in 2006 with my late wife, it has a fiberglass shower alcove w/ separate garden tub in the master bath and it was and still is solid as a rock -- the entire floor. 13 yrs later it still looks like day one. Still clean with a nice sheen !! P.S. You ever think the reason they never weathered for very long in an apartment was because ... Renters? i.e. lack of proper regular cleaning and upkeep.