Options for raised bathtub platform

Question

We are building a new 6' x 15' bathroom with a 6' x 7' area which will contain a shower and a stand-alone tub. The shower pan will be 6' x 3.5' and we are planning to build a small raised platform (6' x 3.5' x 4") for the bathtub to sit on. We are currently planning to tile the top of the platform. We are not planning to have any barrier between our shower and tub. Our contractor thinks that we need to have the platform sloped toward the shower pan so that water that may splash onto the raised platform drains off.

I don't really like the idea of not having a level surface for the tub, and I am wondering if (1) the slope is necessary? (2) if there are other ways to deal with the water that may get on the platform?

This is the bathtub being used: https://www.homedepot.com/p/Vanity-Art-Versailles-59-in-Acrylic-Flatbottom-Freestanding-Bathtub-in-White-VA6610/305086229

Answer 1

No slope is a bad idea - sure, you can have the joy of vacuuming up water on the platform after every shower or bath...no, really you want drainage.

If the tub (as usual) stays put, you can set the tub level, and slope the surface around it (or under it, other than where the feet sit, if it has feet) to drain.

Honestly, my first thought here is that the tub base/surround should be a non-raised extension of the shower base. A step like that invites falls in the bathroom. You step out of the tub, it's further down to the shower floor than your brain expects, or you slip off the narrow step, and hurt yourself.

It should still be sloped to drain, while the part exactly under the tub should be level (and full of plaster, since I'm old-school that way with making plastic tubs be solidly bedded. Tubs that flex, crack.) Either raise the side towards the drain to be level, so the tub sits on a very short plinth, or let the surround base & tile flow up the skirt of the tub to embed it the half-inch to an inch it might need on the high side.