Confirmation on proper tub installation

[llavey]

I have read many of the posts on installation of tubs with a mortar bed and hate to start another, but would appreciate conformation on my understanding for my situation. Thanks in advance for your input.

Tub = Jason Air Tub

This is being installed in a wood frame with a tile surface and tile on the two walls it sits up against in a corner. Underneath the tub is gypcrete. The lip of the tub currently holds the tub 2 ½” off the floor. To properly support this I am planning on the following:

- Build a wood box to support a 2 ½” mortar bed under the tub
- Fill the bed with mortar and create piles on the top of it
- ??? lay plastic down between the tub and mortar bed, not between the mortar bed and gypcrete
- Set tub and “squish” it into the piles of mortar until the upper lip is level with my tile surface
- Let sit for a day before proceeding

After this has been completed I can install my fixtures, drain and finish the tile on the wall around the tub.

Thanks again for your comments,
Link

[jadnashua]

I also have a Jason air tub...mine came with a formed foam panel on the bottom designed to sit flat on the floor holding the tub nice and level (assuming the floor is).

You should be able to do what you are planning, but the box may not be necessary if you use deck mud. I'd also consider a sheet of plastic on the gypcrete. This will stop it from wicking moisture out of the mix which makes it weaker. Deck mud is 4-5:1 sand to portland cement mixed and wetted enough to hold into a ball when you grab and squeeze a bunch. It should not be wet enough to drip when you do this.

If yours has the same foam panel molded to the bottom, you could build a raised platform for it to sit on. The mortar would account for any inconsistencies in the floor, but I'd expect the gypcrete to be dead level, so a platform could work as well.

[llavey]

Jim,

Thanks. My tub does have the same foam on it you are describing. The gypcrete is not perfect but its not bad... I had not thought about the gypcreate pulling the moisture out of the mortar, I will use plastic under the platform.

Thanks,
Link