MiamiCanes
New Member
I'm going to be replacing my bathtub next weekend. The old bathtub is a 72x42 cultured marble tub. The new bathtub is the same size, but acrylic. Since I'm not going to really know the full scope of the job ahead of me until I get the old tub out (at which point I'll be without a bathtub until the new one is in place, because I only have one full bathroom), I'm planning for the worst and just taking for granted that the floor won't be level.
The question is, what kind of formwork do you use to keep the self-leveling cement from running beyond the footprint of the tub? Or... do I even WANT to keep it from running beyond the footprint of the tub? I'm guessing that in a perfect universe, the floor would already be relatively flat & SLC wouldn't run far anyway... but I've learned the hard way that perfection in building construction is a delusional fantasy, and any strategy that depends upon an existing floor actually being level, or a wall being square, or anything being within 1/8" of what it's theoretically supposed to be, is a recipe for expensive disaster ;-)
The best idea I came up with so far is to buy 1x2 furring strips, fasten them to the concrete slab with caulk around the footprint of the new tub's base (where it actually comes in contact with the floor), fill it with SLC, then pry up and remove the furring strips (hence the use of caulk) when it cures.
The thing is, can I assume that if the surface upon which the tub sits is "perfectly" flat, everything will be OK? Or do I have to assume that the tub's underside WON'T be perfectly flat, and it'll still be necessary to have a squishy layer of mortar under the new tub when I lay it in place to fill any voids that would otherwise exist? Likewise, how do acrylic tubs achieve sloping floor surfaces? Do they make the acrylic thicker at the rear so the underside of the tub can be perfectly flat and level, while the surface slopes properly towards the drain? Or do I myself have to give it a sloping floor surface to allow it to slope towards the drain without leaving a gap between the tub's underside and the floor it's supposed to be resting on?
BY the same token... does mortar chemically bond with cultured marble, fiberglass, or acrylic? If the original builder set my current (cultured marble) tub on a bed of wet mortar when he installed it, am I going to need crowbars (or worse) to pry the old tub away from it? Or will the old tub lift off like cookies on a teflon baking pan, and the worst thing I'll have to deal with is a rough surface that mainly just needs to be smoothed out for the new tub?
The question is, what kind of formwork do you use to keep the self-leveling cement from running beyond the footprint of the tub? Or... do I even WANT to keep it from running beyond the footprint of the tub? I'm guessing that in a perfect universe, the floor would already be relatively flat & SLC wouldn't run far anyway... but I've learned the hard way that perfection in building construction is a delusional fantasy, and any strategy that depends upon an existing floor actually being level, or a wall being square, or anything being within 1/8" of what it's theoretically supposed to be, is a recipe for expensive disaster ;-)
The best idea I came up with so far is to buy 1x2 furring strips, fasten them to the concrete slab with caulk around the footprint of the new tub's base (where it actually comes in contact with the floor), fill it with SLC, then pry up and remove the furring strips (hence the use of caulk) when it cures.
The thing is, can I assume that if the surface upon which the tub sits is "perfectly" flat, everything will be OK? Or do I have to assume that the tub's underside WON'T be perfectly flat, and it'll still be necessary to have a squishy layer of mortar under the new tub when I lay it in place to fill any voids that would otherwise exist? Likewise, how do acrylic tubs achieve sloping floor surfaces? Do they make the acrylic thicker at the rear so the underside of the tub can be perfectly flat and level, while the surface slopes properly towards the drain? Or do I myself have to give it a sloping floor surface to allow it to slope towards the drain without leaving a gap between the tub's underside and the floor it's supposed to be resting on?
BY the same token... does mortar chemically bond with cultured marble, fiberglass, or acrylic? If the original builder set my current (cultured marble) tub on a bed of wet mortar when he installed it, am I going to need crowbars (or worse) to pry the old tub away from it? Or will the old tub lift off like cookies on a teflon baking pan, and the worst thing I'll have to deal with is a rough surface that mainly just needs to be smoothed out for the new tub?
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