i contracted to have a fiberglas tube base set in a new cabin that I am building. They did not set the tube in a quick set cement base. I was able to access the back of the tub so lined the tub cavity with plastic over the sub floor and was able to compact cement in the cavity under the tub. I expected the concrete to set solid within a day but it has never set solid. When I stand in the tub I can hear and feel liquid squishing under my feet.
The tub is fiberglas and boats are made of Fiberglas and they float so I am not worried about the integrity of the tub. The squishing sound and feel does not sit well with me.
The concrete mixture was mixed correctly but I think because of the plastic liner it did not get air and set correctly.
Any ideas on how to drain the water without destroying the tub?
Thanks
Ultraglide62

What water are you wanting to drain? Concrete will set up hard under water, so being on plastic will have no affect. What does the tub manufacturer say about filling under the tub?

If you filled the tub with water so that the weight kept it down in the concrete, you should either A)Let the concrete finish curing or Drain the water and disconnect the drain and water supplies and set the tub again. If you use Durabond 90, you will have 90 minutes from the time that water hits the powder to get the tub in position correctly and get some weight in it. Figure at least 15 minutes less because it starts to drastically harden in the last few minutes. The last corner tub I set like that we used plastic below and on top of the durabond in case anyone ever had to remove it.



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I do not know what you used or how you mixed it, but concrete "sets up" within an hour or so, then continues to cure. It does NOT stay soft for days and weeks.

scoop it all out and fill the space with minimal expanding foam. if you have walked in the tub before the cement was set, you may have created ad 1/4 space between the two..

Thanks for your responses. Apparently putting the concrete in plastic was not the problem. I will continue to research my problem. I sure hope the tub does not have a leak! I did put water in the tub and at that time I did not find any leakage.
Ultraglide



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