Need to replace one-piece fiberglass shower/tub

[Zanne]

Now that I'm waiting for my septic tank to be installed, I'm thinking ahead to the project of my mother's bathroom.

Currently we have an avocado one piece shower/tub combo tucked into an alcove.

I couldn't find the thicker measuring tape and I'm all thumbs when it comes to the flimsy measuring tapes. I had trouble trying to get in to the corner on the end while still holding the thing in place. From wall to wall it was about 59.5". From the back wall to the front of the unit was about 31.5". The height of the unit was just under 6'. The height of the front tub wall from the floor was about 13.5". I know these are not exact. The walls behind/around the unit are somewhat thin wooden panels with a texture printed on them. You can see a bit of that in this picture of the tub.

As you can see, the tub spout and handles are sticking out-- which I know is very bad since water can get in there. The hot water handle has to be turned clockwise and is turned a lot before it even starts to come on. The cold water turns counter clockwise. My father kept replacing the handles but something inside kept stripping. Whenever I'm turning the hot water on and off, the entire fixture (both handles and faucet) move forward and backward. There are no access panels to the plumbing.

Here is the shower head. The rusty colored stuff against the unit is actually the color that comes out of the hot water (and sometimes cold). The hard water has stained everything-- including white clothing put through the wash.

Here is the spot on the floor where the tub floor cracked. My brother sprayed it with Flex Seal-- hence the splatter on the walls as well.

This is the matching sink. You can see the rusty color there too.

The toilet used to match until we replaced it with a Toto Drake

I know the floor needs to be cleaned. LOL.
The bathroom is a cluttered mess-- and yes, that is a boomerang on the floor. I have no idea why it is there. I will have to kick my brother for leaving hair on the floor.

The linoleum is torn up because a few years after having it put in (replacing the carpet that had been in the bathroom previously) the floor gave out the toilet tipped over with my brother on it. The floor joist saved him from going all the way to the ground. A very rough patch job was done on it (and I will need to re-do the entire floor because we discovered there is no subfloor-- no moisture barrier).

The tub does not drain well at all. Water pools up toward the crack. While we were overseas the tenants tore out a bunch of the plumbing under the house and when we got back, the shower was no longer connected to the septic system and was just dumping under the house. All of the plumbing vents had also been removed. The plumber put vents in and hooked the shower drain back up, but I don't know what the problem is with the draining. Maybe there are clogs.

The doorway to the bathroom is 23" wide IF we take the door off. I forgot to measure the height, but its high enough for my 6'3" brother to go through without ducking-- but he does have to go through the door sideways because of his girth.

My mother has diabetic polyneuropathy and has trouble with her legs. It makes it difficult for her to lift her feet high enough to get in to the shower. She wants a tub that is either just as shallow if not lower (I think preferably she wants something lower) that will let her step in and out. She wants grab bars to hold on to as she gets in and out. Also, since she is the Queen of Clutter, she wants some sort of shelf space in the shower. I have no idea why there are so many bottles in the bathroom.
Too bad the Stowaway Bathtub is a UK thing

.
That might be nice for accessing the pipes and such under the tub-- but obviously my tub is closed in on 3 sides.

So what we need:
1. Shallow tub (13.5" or less)
2. Sturdy enough to hold 350lb brother who clomps around like a Doofusaurus.
3. Easy to clean with septic tank safe materials.
4. Built in grab bars or ability to have grab bars added
5. Shelf space for putting soaps, shampoos, etc.
6. Preferably inexpensive and easy to install
7. Drain on right side

Now, my mother despises tile, so putting tile around the tub is out.

Any suggestions for types of tubs and surrounds?

I personally like the look of this:

But I would want corner shelves and more space. Plus I measured that thing and I would have to move the location of the shower head to not jut through one of the decorative parts that pokes in. I've read that the pockets are rather flimsy but spraying them with grate stuff or some sort of expanding foam crud would make them sturdier.

 

[johnjh2o]

You need more help then you can get here. Need a remodeling contractor.

 

[Zanne]

You need more help then you can get here. Need a remolding contractor.

Remolding or remodeling?

I hope I can find someone because its hard to find people out here. Particularly hard to find reliable people who don't charge an arm and a leg.

Other than finding the right contractor, does anyone have any suggestions on what products are good and which ones to avoid?

I've heard Sterling is good, but what about Aquaglass?

 

[havasu]

I've only installed one ready made tub with the 5 piece plastic/fiberglass walls, and it was way too flimsy for my liking. I'd recommend purchasing a better one from a qualified plumbing/hardware supplier, and installing it yourself. Unfortunately, this itself will not correct your galvanized rusted iron pipes, so if you could find the money, a copper pipe replacement along with a new tub would be your best bet.

 

[Zanne]

I've only installed one ready made tub with the 5 piece plastic/fiberglass walls, and it was way too flimsy for my liking. I'd recommend purchasing a better one from a qualified plumbing/hardware supplier, and installing it yourself. Unfortunately, this itself will not correct your galvanized rusted iron pipes, so if you could find the money, a copper pipe replacement along with a new tub would be your best bet.

Thanks. I don't know if I could install it myself. I'm not all that confident yet. I'd like to start with doing a smaller project before taking on something like that.

Finding a qualified plumber in this area isn't the easiest and as for suppliers, there aren't as many options as I would like. I live in an area that doesn't really offer much. There is a small Coburn's as well as one Lowes and one HomeDepot -- all of those are an hour away. There aren't any of those stores in my entire county/Parish.

I know I'm going to have to look though. I would like to at least try to narrow down the products to use though.

 

[stevemachine]

Maax isn't bad, not sure if they make a tub to fit your criteria. HD should carry them. In my opinion for the most part you get what ya pay for. Obviously there's a difference of overcharged. Do some research and find out who has the best price in your area for a tub that will meet your needs. Maybe get the few plumbing contractors in your area to give you some quotes. You have to start somewhere if your not confident in doing in by yourself. I find sometimes tubs requires two guys anyways, it's doable if your alone but it's nice to have two people. It might suck but you may just have to bite the bullet.

 

[Zanne]

Maax isn't bad, not sure if they make a tub to fit your criteria. HD should carry them. In my opinion for the most part you get what ya pay for. Obviously there's a difference of overcharged. Do some research and find out who has the best price in your area for a tub that will meet your needs. Maybe get the few plumbing contractors in your area to give you some quotes. You have to start somewhere if your not confident in doing in by yourself. I find sometimes tubs requires two guys anyways, it's doable if your alone but it's nice to have two people. It might suck but you may just have to bite the bullet.

Thanks! Yeah, I know I will have to try to find good contractors. It's hard to find reviews on people in my area for some reason, so I guess I will have to call around. One of my father's dive buddies gave us the name and number of a general contractor that has done work for him. We don't really know a lot of people in the area so that is part of the problem. It doesn't help that we get conflicting opinions. One person will say someone is good and another will say that person is terrible. We did have a good contractor who did some work on exterior things before, but he passed away a couple of years ago.

At least four people who did some work for us passed away in the past few years-- a few from the ailments of old age and one from cancer.

Now the question is whether we want to have the bathroom renovated or replace the pickup truck that was totaled by the falling tree limb. The pickup could come in hand, but I'm worried that the longer the bathroom is left as-is, the worse it will get and the more expensive it will be to fix it.

 

[stevemachine]

yeah fair enough I know what you mean. You'll have to decide what's gonna be best for you. Unfortunate, hopefully things start turning around for you. Sounds like you've been having your share of issues lately.

 

[Zanne]

yeah fair enough I know what you mean. You'll have to decide what's gonna be best for you. Unfortunate, hopefully things start turning around for you. Sounds like you've been having your share of issues lately.

Oh yeah, and another one arose this morning. First the septic tank installer called me to tell me that the concrete for the tank they poured last week is still too hot and they don't want to take it out of the mold for fear it will crack and they are postponing until tomorrow. Then the draining guy came out to drain and then refused because he said it would have to be drained tomorrow just before the tank was filled in. He also claimed that I picked a bad installer and that he was one of the worst and then claimed that he thought the health inspector took bribes from that guy and another installer. I looked at the BBB and there were no complaints about the company and of the two guys my draining guy suggested, one was too busy and the other wanted to do an installation that was not to code. And the draining guy was looking at me as if I were stupid when I explained the code states that the field lines cannot be over 100ft. He tried to argue that maybe certain materials or types of field line can go over, but I talked to the health inspector and he said "no".

My gut tells me the draining guy is full of it. I just hope I'm right.

Anyway, he's coming back to drain tomorrow but he's charging extra because he came out today and didn't drain it.

Meanwhile, I was looking at this tub and surround as a possibility:
http://www.homedepot.com/p/Sterling...in-in-White-71220120-0/100675607#.UVmhBRzV7UC

 

[stevemachine]

That tub and surround looks pretty decent. It's a start for sure.

 

[havasu]

I was also impressed with the sturdiness and pleased with the other's ratings on it.

 

[Zanne]

I was also impressed with the sturdiness and pleased with the other's ratings on it.

Yeah, the Aquaglass ones that were pretty and shiny had some bad ratings. Funny thing on that tub and surround is that as I was at homedepot website, a thing popped up inviting me to chat with a customer service rep. I told her what I was looking for and she linked me two Sterling tubs. The one I linked was one that had already been on my list of possible choices. She also gave me the number for Home Depot's service for having things installed. Apparently they have consultants who would look at the bathroom and determine what was needed and such. But, its hard to tell if they would be getting someone reliable.

But with the water pump now no longer working so we don't have running water and the installation of the septic tank postponed until Friday (or the following Friday), this is a project that will have to be put off for longer.

I do want to figure out what materials I will need for the whole project. I'm probably going to have to either rip out the existing floor and create a sturdier subfloor with moisture barrier, or I can just fortify the existing floor and put down a moisture barrier and another layer on top, which will raise the floor level a little bit. Maybe if I use something thin as the top layer it won't be too much of a change. I may have to replace the floor under the tub because I bet its moisture damaged. I'm expecting mold and water damage in the walls.

I'm pondering getting PEX instead of metal piping, but I doubt that is mouse proof or possum proof. I don't know if possums would chew that stuff, but I don't want to take chances. I think there might be a possum in the attic. There was one possum that got in and ran loose through the kitchen and then into the great room.

I really should learn to play a banjo or something while I'm out here.

 

[Zanne]

Apparently Aquaglass is discontinuing all of its products.

Anyway, I was a the store and I saw a surround by Maax for $199.

But I'd need to get some grab bars installed. I also don't know if it is deep enough. But my mother liked it.

 

[Zanne]

I know I'm necro-ing an old thread here, but I might finally have enough $ left over from my settlement for medical + pain and suffering from the car accident last year.

The sterling one I linked is no longer available and my mother has vacillated between wanting a tub and wanting a shower.

Since I last posted here, my mother's mobility has decreased. She has inner ear damage which causes balance problems and she has difficulty lifting her legs enough to step in to a tub. Even with a shower seat, she can't manage to get in without slipping (and we don't have grab bars installed bc we still plan to rip out that fugly green thing). The suction cup grab bars did not work.

I know they make shower units that are the same size as tubs, so I'm starting to consider replacing it with a shower that has grab bars.

The DWV for my house is going to need to be completely re-done so I might not get some of the issues that we currently have with the tub not draining quickly enough during showers and it almost fills the tub-- that is because I'm sure it has clogs, nothing is sloped properly, and there is no vent.

Now, whether I go with tub or shower-- the plan is to go with one of those 4 piece units that fit directly to stud and don't need caulking (but can still be caulked). It's basically the back as one piece, the sides separate, and the tub or shower pan.

I'm still thinking of going with sterling, but I'm curious about how different a shower install is from a tub install. Is it more difficult to install a shower pan? I would be going with one that is relatively the same footprint as the existing shower/tub unit and has a right side drain (like the existing tub).

Although, I'm also considering maybe a 48"x30 or so shower so the shower seat can be closer to the spout and controls (and then I an put some storage shelves or something in the gap. I can't seem to find one with a built-in seat that is large enough for my mother since she is "morbidly obese" (she's at 240lbs but her hips are huge-- she actually has fat that forms shelves on her hips), so we will have to use a freestanding bariatric one.

Glass doors would be a pain to install, so I'm wondering if shower curtains can be used instead. I was thinking of putting a magnetic strip inside the edge of the lip of the shower pan (basically on the underside of it so it won't be on the surface) and then getting/making a shower curtain with magnets in the bottom to help hold it in place.

If we go with a 60" shower unit, we can probably scoot the shower seat forward for her.


For the showerhead I'm thinking of going with moentrol valves and of getting a Moen Magnetix showerhead so it is easier to dock and remove.
http://www.homedepot.com/p/MOEN-Att...o-Kit-with-Magnetix-in-Chrome-26008/207032918
or
http://www.homedepot.com/p/MOEN-Att...PIPHorizontal1_rr-_-207032918-_-206827175-_-N
(leaning toward the first one because I don't like the plastic thing on the 2nd one).

Other than Sterling, I saw some sort "Aquatic" brand at HD and it felt very sturdy-- it seems to be some sort of composite. It goes direct to stud and it had non-slip surface on the bottom-- but it was filthy so I wonder if it would be a pain to clean. Also, I found it in a tub/shower combo but I did not see just a shower.

So, any ideas or suggestions?

 

[Zanne]

I am necro-ing again because we've been talking about this renovation again. My mother would really like to have a shower she can step in to easily.

The one I previously linked on HD is no longer available (at least not at that link) and has skyrocketed to over $1k in price on the Lowes website.
So, right now the options are the Sterling Ensemble sans backers 72170120-0
https://www.lowes.com/pd/Sterling-E...on-30-in-x-60-in-Actual-30-in-x-60-in/4423824
specs:https://68.media.tumblr.com/38ee8d16e6934ebb87e740b2a4049307/tumblr_onogmm4sO51qkwd9ao1_1280.png
Direct-to-stud walls are 1-5/8" thick and the front threshold is 3" wide; this leaves an interior measurement of approximately 56-3/4" L x 25-3/8" W for shower seat.
It is $642.01 before tax (10.5% tax at nearest Lowes but we get a 10% military discount prior to tax). It's $622.75 on HD but out of stock and price can change by the time it's in stock. With the military discount it would end up being cheaper at Lowes.

Pros: Durable, can have grab bars installed with proper backers put in the walls, good ratings, looks nice, easy to clean, easy to step in to, easy to install, & can fit shower seat
Cons: Expensive, not in stock at local store, can be damaged in shipping, wall of adjacent closet will need to be notched to fit since it is 59.5" and shower is 60"+, & requires modification to add grab bars
--
Another option would be to get the Delta Classic 400.
Walls for $360 https://www.homedepot.com/p/Delta-C...Stud-Alcove-Surround-in-White-40104/204342331
Shower pan for $189 https://www.homedepot.com/p/Delta-C...wer-Base-in-High-Gloss-White-40094R/204342329
Pros: In stock at HD, lower price, easy to install, good shelf space, might be eligible for military discount, less than 60" so might be easier to fit in
Cons: not sure if it's as sturdy as Sterling, price tends to vary frequently, not sure if grab bars will fit on back wall due to curves/design, will require modification for grab bars, not sure on exact specs just yet.
--
For the side grab bar, I'm thinking of going with the Moen Model # LR2356DCH 16" grab bar with a little shelf. Not sure if that will be long enough for the Sterling or if it will be short enough to fit in the Delta.

I've watched several videos on grab bars and installation but most seemed to be over tile or cementboard. I haven't seen any good ones on how to install in an acrylic/fiberglass shower. I know with my current one they put wood directly against the fiberglass where holes were drilled for handles, but I am not sure exactly what to do on the fiberglass ones because there is a bumped out part that is not flush with the studs. I know I can add backers between the studs, but there may be a gap between the studs and the wall panels unless I bump the supports out at the right spots and/or find anchors that will go in far enough to reach the studs/backers without making the fiberglass cave in. I'm guessing the bump-out supports will be the way to go.

Another uncertainty is the showerhead. My mother decided she wants a slidebar, which rules out the showerheads I listed previously as Moen says they will not work on a slidebar. I have multiple options for configurations thus far, based on what I've been seeing for sale.

1. Traditional style with stationary showerhead on arm with diverter to a drop ell attached to a hose leading to a handheld showerhead docked on a slidebar secured either under the other showerhead or off to the side.
2. Traditional style with stationary showerhead on an arm adapter that splits flow from main shower to hose (eliminating need for drop ell)
3. Space saving style with handheld shower docked in a slider that fits on a grab bar w/ hose connected to a drop ell with a stationary showerhead & diverter
4. Space saving style with handheld shower docked in slider on grab bar but with hose going to shower arm w/ no diverter
5. Space saving style with handheld shower docked in slider on grab bar with hose going to adapter/diverter on shower arm w/ stationary showerhead.
6. Economic style with top of slidebar hooked to shower arm, receiving water flow with an outlet near the bottom where hose for handheld attaches. Bottom of slidebar secured with suction cup

With 1, it is traditional enough that it might help with resale value, although that is not much of a concern. But, it would require more valves, more holes, and more water supply lines & would ultimately be more expensive.
With 2 there would not need to be extra valves, but diverter location would be important so that Mom can reach it easily.
With 3 it would save the need to drill more holes and save the $ on buying a full slidebar, but it would require specific grab bars to be fitted with the Moen or Delta pieces that dock on the grab bars. They also tend to be plastic and not that great looking. It could impact the location of the grab bar as well. The drop ell & valve would be more expensive.
With 4 it would save money by not having the diverter or drop ell & save labor on not having to drill more holes. Same perks #3 as well, but would also have the proprietary fit and being fugly issues.
With 5 it would be about the same as 3 & 4 but would be in between the pricing bc there would be an additional showerhead and need to find some way to turn the diverter.
With 6 it would eliminate the need for a drop ell & you wouldn't need an upper showerhead (unless there was a kind with an adapter to have an extra one) so it would save $. Only issue is, it seems to be an off brand that makes that style & I haven't seen any from Moen or name brands I'm familiar with.

I'm sort of leaning toward 4 or 5 or 2. As nice as the drop ells look, I think it would be more efficient to have the hose hook to the shower arm and haven an accessible diverter either on the handheld or on the slidebar. I need to see options bc if we go with 2 showerheads, it would be essential to be able to turn off the top one and handheld at the same time.

I'm also trying to figure out best mounting locations for things, what length slidebar/grabbar to have, what sort of handheld, etc. I know a lot of it will depend on what my mother thinks of how things look, but she also trusts my advice on a lot of things so she will defer to me on some issues (but gripe at me if she ultimately doesn't like it).

So, any suggestions? Pictures, links, etc would be greatly appreciated.

As an aside, we already purchased the Moentrol 3510 IPS threaded valve & the Moen Kingsley moentrol trim kit for the shower (although we got them a lot cheaper than HD had them).

 

[Jamesplumbing06]

Man. All this time I thought you a plumber. Lol. My bad. You sound like you know your stuff in threads. Any experienced plumber would tell to get a metal cast tub and tile the wall to ceiling. Fiberglass cracks and no place to hang grab bars. At least get a bid. And being for a mom. She might like just a floor ceiling shower. No apron to step over. Nice little bench in the back. But don’t call the guy that fixed your floor. Tile needs to be paid for and done correct. I dunno how. That’s on the tile guy.

 

[Zanne]

Thanks, James. I admit it's an ego boost to know people think I'm a plumber. I find plumbing fascinating and have been trying to learn as much about it as I can.

I really appreciate the feedback.

We are getting rid of the tub and going with a shower. Getting the curbless kind wouldn't work because we'd have to slope the floor & add a floor drain, which would be a royal pain to do properly. I actually looked in to the costs and logistics of doing a "wet room" shower and after discussing it with her, she ruled it out as an option. Mom absolutely *hates* tile for some reason. I'm not very fond of it myself. She also doesn't want to put too much $$ in to fixing the place up. I'm personally paying for the laundry room & other bathroom reno and may end up paying for some of this bathroom, but my budget is $5k to spread over both.

The Sterling is made of something called Vikrell and is reportedly very sturdy. The shower pan has a grid pattern underneath to give it support. The Delta one is acrylic and has foam underneath. I haven't even seen metal shower pans available in my area. I'm looking for something I can lift that will be relatively easy to install. I'll be doing it myself (possibly with the help of some friends for heavy lifting).

There are currently no licensed residential contractors in my area. (I have looked on yellowpages, angieslist, home adviser, etc). There were only two of them and they both died years ago. I'm in a "No Man's Land" of services. My good plumber died almost a decade ago. There are only two plumbers now and both of them are hacks and only one of them will come out here. He's the one that has been barred from working in a larger town (he can't get licensed there for some reason). The inspector already told me that due to where I live, I don't need to pull permits to renovate.

We already have the vinyl sheet to put in the bathroom for when we fix it up and it should be easier for me to put in than it was in my own bathroom (bc hers is just a rectangle without all the bump-ins mine has). I'm planning to replace the floor and have two layers of plywood instead of one (which is what we have currently). My father is the one who patched the floor with OSB when the toilet fell through it. Never got around to hiring someone to fix it properly due to his health issues. He was the one who handled repairs, contractors, insurance etc-- up until about a year before he died. Then I started taking over on handling insurance adjusters & doing more of the repairs, but I was never as good at it as he was.

The Moen Kingsley shower trim arrived today and my mother liked it-- said it looked better in person than it did in pictures. I need to get her to the store to look at the shower surround options. I've touched the Delta one in the store & seen it installed in a friend's place and it feels sturdy. Sterling feels sturdy as well-- better than the fiberglass yuck we have now. I wish some of the other Delta options didn't have the fake tile look because Mom hates it. She wants just plain smooth white.

In the long run, I'm hoping to paint the shelves, the cabinets, the countertops (or at least refinish them & the sink so the sink isn't green), replace the window with something more energy efficient, & replace the vent-light-heat-fan in the ceiling. But getting the shower sorted out is the priority.

I'm uploading a quick rough sketch of the layout/measurements. B2 is the bathroom discussed in this thread. I need to make a better sketch.

 

[Geofd]

for the tub have you thought about a walk in style??????if your mom is having issues there is a door that opens and a seat????just a thought

 

[FishScreener]

Thanks, James. I admit it's an ego boost to know people think I'm a plumber. I find plumbing fascinating and have been trying to learn as much about it as I can.

I really appreciate the feedback.

We are getting rid of the tub and going with a shower. Getting the curbless kind wouldn't work because we'd have to slope the floor & add a floor drain, which would be a royal pain to do properly. I actually looked in to the costs and logistics of doing a "wet room" shower and after discussing it with her, she ruled it out as an option. Mom absolutely *hates* tile for some reason. I'm not very fond of it myself. She also doesn't want to put too much $$ in to fixing the place up. I'm personally paying for the laundry room & other bathroom reno and may end up paying for some of this bathroom, but my budget is $5k to spread over both.

The Sterling is made of something called Vikrell and is reportedly very sturdy. The shower pan has a grid pattern underneath to give it support. The Delta one is acrylic and has foam underneath. I haven't even seen metal shower pans available in my area. I'm looking for something I can lift that will be relatively easy to install. I'll be doing it myself (possibly with the help of some friends for heavy lifting).

There are currently no licensed residential contractors in my area. (I have looked on yellowpages, angieslist, home adviser, etc). There were only two of them and they both died years ago. I'm in a "No Man's Land" of services. My good plumber died almost a decade ago. There are only two plumbers now and both of them are hacks and only one of them will come out here. He's the one that has been barred from working in a larger town (he can't get licensed there for some reason). The inspector already told me that due to where I live, I don't need to pull permits to renovate.

We already have the vinyl sheet to put in the bathroom for when we fix it up and it should be easier for me to put in than it was in my own bathroom (bc hers is just a rectangle without all the bump-ins mine has). I'm planning to replace the floor and have two layers of plywood instead of one (which is what we have currently). My father is the one who patched the floor with OSB when the toilet fell through it. Never got around to hiring someone to fix it properly due to his health issues. He was the one who handled repairs, contractors, insurance etc-- up until about a year before he died. Then I started taking over on handling insurance adjusters & doing more of the repairs, but I was never as good at it as he was.

The Moen Kingsley shower trim arrived today and my mother liked it-- said it looked better in person than it did in pictures. I need to get her to the store to look at the shower surround options. I've touched the Delta one in the store & seen it installed in a friend's place and it feels sturdy. Sterling feels sturdy as well-- better than the fiberglass yuck we have now. I wish some of the other Delta options didn't have the fake tile look because Mom hates it. She wants just plain smooth white.

In the long run, I'm hoping to paint the shelves, the cabinets, the countertops (or at least refinish them & the sink so the sink isn't green), replace the window with something more energy efficient, & replace the vent-light-heat-fan in the ceiling. But getting the shower sorted out is the priority.

I'm uploading a quick rough sketch of the layout/measurements. B2 is the bathroom discussed in this thread. I need to make a better sketch.
View attachment 18972

You should reframe the wall you need to notch, and just put the 2x4 studs, on the flat, that narrows the wall 2-inches.

 

[Mikey]

I just finished a Kerdi no-barrier shower. No fancy mud pan, no greenboard walls. Just frame the walls true and use regular gyp board, profile the floor to the proper slope, cover everything with the membrane, and tile your heart out. Moderately expensive, more expensive if you use all Schluter products, but they do warrant their products pretty well. But you do need a floor drain, and you slope down from the existing floor, which may be a problem. And, of course, if Mom hates tile, this is a nonstarter.

Back to reality, if you've got access to the other side of the shower walls, put the backer boards for the grab bars in after the shower is installed. Then you can push them up against the back side of the fiberglass and screw the grab bars up tight. Look into grabbarspecialists.com for reasonably-priced and attractive products. You might be able to epoxy-bond 2x4s to the back side of the shower walls before they're installed - all you really need to do is spread the point loads of the grab bar fasteners over a broad area, and the fiberglass should support it. We ripped out a fiberglass-like shower when we did the new shower, and it was pretty hefty -- at least 3/8" walls and it weighed a ton.

Free advice, and worth every penny...