Air jet Tub and Mortar Support?

Hi everyone,

I am about to install a corner, drop in, air jet tub, and have a question surrounding the use of mortar as base support.

How do you use mortar as a base support when the airjets are bottom mounted? This is an acrylic, fiberglass backed tub. If I use mortar the jets will either be completely surrounded, or my fear is that all of the potential "flex" will pass into the air jet bodies, thus damaging the air jet system.

The manufacturer instructions are generic to a drop in tub and indicate that NOT using mortar will void the warranty. How does this work?

Thanks in advance!

The point of using mortar is to eliminate flex.

Put a sheet of visqueen plastic between the tub and the mortar so the compenents are NOT encased in the cement.

Thanks for the responses.

Is it okay to build up the "space" requirements with a Quickrete mix, let that set, and then use mortar to fill the final small gap? We are looking at approximately 3.5" of space to build up.

Can you recommend a good brand of mortar mix that would work well for ensuring coverage around the airjet bodies? This would seem to need to be a very "soft" and grainy mix to ensure proper distribution around the components...?

You can also build up using wood if needed. I like to leave some space between for the mortar, but not too much.
When I drop the tub, I use piles that will squish out. Do not lay a flat bed of motar, it won't be the right height, and will set before tub can be set.
Like hj mentions, a sheet of bisqueen between tub and the mortar is good.

Thanks again, sorry to be a pain...one final question 'cause I want to get this right...

To build up with wood, would I build a basic "deck" platform, sort of like an additional subfloor with 2x2's and 3/4 ply, to span the base of the tub with cutouts around the existing feet, and then apply the mortar to that and a little under the feet themselves to ensure a good fit? I presume I would then need poly both between the "decking" and the mortar as well as between the tub and mortar?

You guys have been a great help! Thanks again!

A little pan of 2"x2"'s will help keep more mortar under your tub.

You can use any good mortar mix for setting bricks - like mentioned above I place as well the mortar mix in a pile larger than needed by at least 3-6" and then a sheet of plastic (6mil poly) and then gently lower the tub. The tub should be supported by it's leveling legs and the mortar should just fill in the voids under the tub. Fill the tub with water and let it set up overnight.

You'll be have your first bath in no time...