Install grab bar in fiberglass shower

[ballard770]

I need to install grab bars in our fiberglass shower and I’m concerned with the fact that I may not be able to fasten it to a stud. If I fasten it to the fiberglass enclosure only I don’t know how sturdy it would be as it flexes. If I find a stud the fiberglass may still be too flexible. In checking instructions for one set it mentions a kit that looks like it is for Sheetrock and not fiberglass. The points where I would install the bars can vary from about 1”-2” between fiberglass and Sheetrock. It seems to me that there should be a rigid tube between the fiberglass and the Sheetrock but I can’t find any such anchor system. It seems that the manufacturers of the bars don’t want to bring fiberglass showers and tubs into the discussion - perhaps a liability concern.

Any thoughts or suggestions will be appreciated.

Lee

[twistsol]

I honestly would not trust a grab bar with much weight if it wasn't attached to framing. Years ago, my brother in law and I had to make the bathroom more accessible for our father in law and we added blocking behind the fiberglass tub/shower from the other side of the wall and then repaired the sheetrock. Not sure if that is more of an undertaking than you're willing to tackle or even if it is possible in your case.

[Jim Frye]

Glad this isn’t my task. The shower enclosure and tub surrounds in our new home were installed prior to the drywall being hung. I took pictures of all the walls after the roughin and prior to the drywall being hung. The fiberglass/acrylic units have flanges that are screwed to the studs and the sheetrock overlaps the mounting flanges. The bodies of the units stand clear of the studs and there is additional insulation in those areas. The only way I could mount grab bars would be to use moley bolts and adhesive to attach the mounting plates to the unit wall. There are a couple of locally owned “Bathfitter” style firms here that advertise grab bar installation in existing bathrooms. Perhaps one of these would be a solution instead of DIY?

[capncarl]

I added grab bars to our acrylic shower earlier this year. I did a lot of internet research on this subject, they made it sound easy. I didn’t not find a single “easy installation” that I would trust for a towel rack, much less to support a body that might be falling. When we had this house built I remember discussing grab bars in the showers and tubs but it never happened because no one could make up their mind where she wanted them. It was discussed that the contractor would install some framing in the wall for future grab bars. I took photos of all the build but could not locate any such framing, so it didn’t happen.

Here is how I installed mine. ....cut the drywall on the wall behind the acrylic shower. Locate the exact placement of bracing by drilling through the acrylic.
The shower is actually 1 1/2” to 2” inside of the wall studs, so I framed inward toward the acrylic. After the framing was installed I packed plaster of Paris between the framing and the acrylic to prevent the acrylic from being pulled inward when tightening the grab bar screws.

This process worked perfectly, so now you could do chin-up’s on the grab bars. No flexing of the acrylic was noticed when tightening the screws. I feel the use of plaster of Paris or a simular material is absolutely necessary to prevent cracking the acrylic when tightening the screws.

On the wall where the water valves are hidden behind the sheet rock I measured the water lines and valves locations and marked them on the sheet rock after it was finished and painted. This was in my closet and behind hanging clothes and would never be seen by anyone but me..... or future owners. For locations like this I would mark the water lines and valves with blue painters tape and photo the wall before removing the tape and painting,

[LCHIEN]

My thought is that a grab bar has to be solidly anchored and that means into a framing stud. That's because the function of a grab bar will be for you to grab if you have lost your balance and are falling. In which case, forces of several times one's weight can be exerted by acceleration of falling. This may peel away ot rip the fiberglass if the grab bar is simply toggle bolted to the fiberglass, causing the fiberglass to fail when the person falls. A double tragedy.

My first question is, is the fiberglass wall of the tub anchored to the framing? Probably not given that fasteners would be showing instead of an expanse of fiberglass. More evidence but not conclusive would be if you can push on the fiberglass, does it give at all? That would determine if it is flush against the frame or simply floating some distance away.(Like in Capncarl's example.)

If it seems to be solidly against the frame then my next question might be to see if I can see the studs using a ultrasonic stud finding tool. If you can see the studs clearly then all it may take is to use a long enough screw so that the fiberglass is pulled solidly to the frame by the mounting for the grab bar. As usual, you will confirm by feel if you drill and hit a stud!

If you can't do this, then maybe Jim F is right, call an expert. or apply bracing like Capncarl, by working through the back wall.

[Condoman44]

I seem to recall that Moen or Delta make a mounting kit that solves this problem.

I have used SnapToggle with SS screws to do this in the past.

[Carlos]

I went through this years ago, did lots of research on special fasteners that work in this situation, bought some (way expensive), then... I remembered that I have a neighbor who does elder nursing. I asked her about it. She looked at my like I was an idiot. "We just use the ones with suction cups!" Sure enough, the big box had an assortment of them. This was for my mom visiting, and then I left them up to see how well the suction cups would stay. On her next visit a year later, they were still solid.

I did clean the area very well with 91% alcohol first.

[MasterFR]

I added grab bars to our acrylic shower earlier this year. I did a lot of internet research on this subject, they made it sound easy. I didn’t not find a single “easy installation” that I would trust for a towel rack, much less to support a body that might be falling. When we had this house built I remember discussing grab bars in the showers and tubs but it never happened because no one could make up their mind where she wanted them. It was discussed that the contractor would install some framing in the wall for future grab bars. I took photos of all the build but could not locate any such framing, so it didn’t happen.

Here is how I installed mine. ....cut the drywall on the wall behind the acrylic shower. Locate the exact placement of bracing by drilling through the acrylic.
The shower is actually 1 1/2” to 2” inside of the wall studs, so I framed inward toward the acrylic. After the framing was installed I packed plaster of Paris between the framing and the acrylic to prevent the acrylic from being pulled inward when tightening the grab bar screws.

This process worked perfectly, so now you could do chin-up’s on the grab bars. No flexing of the acrylic was noticed when tightening the screws. I feel the use of plaster of Paris or a simular material is absolutely necessary to prevent cracking the acrylic when tightening the screws.

On the wall where the water valves are hidden behind the sheet rock I measured the water lines and valves locations and marked them on the sheet rock after it was finished and painted. This was in my closet and behind hanging clothes and would never be seen by anyone but me..... or future owners. For locations like this I would mark the water lines and valves with blue painters tape and photo the wall before removing the tape and painting,

Thx, it's helpful. Got some troubles now. My mom broke leg, so I'll try to do my best.