I have a fiberglass garden tub in the home I just bought that wasn't installed right. The far side has no support under the lip and as a result it likes to loose its seal to the tiles above. My current solution has been to recaulk it every time it cracks but this has gotten rather annoying over the past few months.

Is it possible for me to rip out the tub and either replace it or fix the supports without redoing the whole shower area? (ie tile and plumbing). Does anyone have any recommendations on howto do it?

1 Answer 1


The tub should be supported underneath where it sits on the subfloor, not just at the lip. Usually the manufacturer specifies that the tub be set into a bed of thinset mortar to make sure it's well supported across the entire bottom surface. We have a tub that's doing the same thing.

The easy fix is to remove all the caulk around the edges, then fill the tub with water before recaulking, only draining the tub after the caulk has had time to dry fully. This ensures that the caulk seam stays mostly in compression even when the tub is full of water and people, reducing the chance that it will get pulled apart. I've done this to ours and it's lasted well so far (granted, it's only been a few months now -- we just moved here in April).

What I'd eventually like to do, as our fiberglass tub still creaks when you walk in it, is to open up the adjacent wall and try to get thinset mortar underneath the tub. My plan is to gently pry the base of the tub upward with shims, then slather mortar underneath as much as possible, and then remove the shims so that the tub settles into the mortar. This might be an option for you, but it might involve some tile work depending on where you can get access to the subfloor under the tub.

I know this doesn't do much to answer your specific question about the feasibility of removing and replacing your tub. That's difficult to answer without knowing exactly how your tub is installed. I have to think that's going to be a big job though, no matter how it's installed.

  • What? That's overkill. My tub I screwed in a few screws along the lip and it was good. And that's all the manufacturer called for. If you mortor in your tun you will never be able to replace it.
    – nportelli
    Sep 10, 2010 at 12:13
  • 2
    If all you used were a "few screws", then you're going to be glad you've made it easily replaceable in a couple of years. It's true that some manufacturers don't specify bedding the tub in thinset, but many do. It just occurred to me -- do you think I'm talking about setting the tub into a tub-sized pool of mortar? That would be completely idiotic. I'm talking about a 1/2" layer underneath the tub to fill any gaps between the tub & floor. It's easy to remove a tub from a bed like this if it ever does need to be replaced. Sep 10, 2010 at 12:55
  • Thanks for the tip! I'm going to try that when it cracks next time. (Before I take the plunge to replace the tub.)
    – chotchki
    Sep 12, 2010 at 17:54

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