Fiberglass crack on shower base

[sloanmer]

I have a fiberglass stall shower. I live in a ranch house built on a slab. The other day, as I stepped onto a section of the base, it caved in slightly and cracked. Is this something I can repair? Will water leak into my foundation if I don't fix it? I have been using an alternate shower.

[irregularjoe]

Yep. It will leak.


Did you ever see OHM'S mother in LAW?...... SHOCKING!

[volts]

sloanmer: A stopgap measure for repairing a small crack is to fill the crack with a fiberglass filler that is used for automobile dents. I once used epoxy for same and it held up well.

[LazyPup]

Before repairing the fiberglass i would think about adding some additional support under the existing base pan. One method that will work is to get a can of the expansion foam that is used to fill gaps for insulation. You could insert the nozzle tube through the gap in the fiberglass and discharge the whole can into the void. It will conform to the underside of the fiberglass and once it hardens it would add additional support.
The fiberglass used to make shower stalls and tubs is essentially the same material used to make boats or automotive parts and fiberglass repair kits are readily available at auto parts stores or boat suppliers.
Repairing fiberglass is somewhat of a messy job but not at all difficult and most of the kits will have all the supplies and materials required to do the job. I would highly recommend wearing a pair of disposable latex gloves because the chemicals used in the resin and hardeners are somewhat of a skin irritant.
Begin by sanding the surface around the patch area. If it is just a crack i would go at least an inch on either side. precut the fiberglass material to approximate size, then mix the resin and hardener per instructions on the package. Dip the fiberglass cloth in the liquid and lay in place, smoothing with a disposable plastic spatula. Depending on the thickness of the fiberglass cloth in the kit, i would plan on at least 3 to 4 layers of buildup. Allow that to harden (dry) thoroughly then finish with gel coat.
Fiberglass gel coat repair kits are available with either a premixed color to match , or some come with mutliple dies and you can mix until you get a match to the color desired. First you sand the fiberglass patch smooth, then brush on the gel coat and let it set. applying gel coat is similar to applying a nail polish, simply brush it on and it is fundamentally self leveling as it cures. You can also sand it and apply a second or even third coat to get the desired finish.

[mrcaptainbob]

Lazypups suggestions are good. Except...(Yeah there's always one of those!) about that expanding foam. Especially a WHOLE CAN! There's two types, high expanding and the low for use around doors and windows. They had to come out with the low expansion stuff because it was bending window frames and cracking walls. That stuff would certainly fill the void that's apparently down there. But the chances of you putting in the exact amount before expansion is not good. It could make a bad situation worse by expanding enough to severly damage that already weakend floor. Sounds to me like the best bet would be to pull out that floor and determine why there's a sag in the first place.

[LazyPup]

if i read the post correctly,,she said it was a fiberglass shower pan over a slab. Typically there is about three inches between the bottom of the pan and the floor. Assuming the shower pan to be approximately 24" x 24" or greater there should be ample room for the foam to expand horizontally filling the void between the concrete and underside of the fiberglass.

[mrcaptainbob]

Hi, Lazy. Not familiar with the fiberglass pans. Will be getting involved with that experience later this year. Why would you suppose that pan flexed enough to crack? Aren't they reinforced with ribbing or some such underneath? Fiberglass is a pretty strong item, so I'm wondering what could have caused it to let go? As for that foam....that is a fair sized area that you describe. The reason for my caution was an experience I had before they came out with the low expansion stuff. I used it around the windows when residing the house. It easily warped the multichannel aluminum frames. It squeezed out both ends, as well as pushed away the moldings on the inside of the house! Fortunately I caught the problem before I did the rest of the windows. Wish they'd've had that low expanding stuff 25 years ago!