Designing Kitchens and Bathrooms - Air Tub install - Mortar bed ques?

Hi all, I just wanted to bounce an idea off you and see if you have any advice.

The tub comes with a foam pad attached to the bottom, they call it a "self leveling" base. I was about to measure for the deck height (drop in installation). I was adding up the tile, cement board etc.. so that the rim of the tub would just sit above the deck but then I remembered the height that the mortar bed creates. How do you account for that? I am thinking of simply setting the tub in with the foam base on the subfloor, checking for level and then laying mortar around the foam base and floor. Any issues with this approach? I think it makes it much easier for planning the deck hieght and not to mention that I wouldn't have to try to level this tub on top of a bed or mortar.

Thanks in advance.

Following the directions per the manufacture for installation. Lack of support causes squeaks, in some cases leaks at drain pipe fittings and worst of all cracks in the finish material. Most manufacturers recommend or suggest installing a mortar base support under the tub/shower bottom before setting units in place. You can use either a bag of Quikcrete or a 5 gallon pail of pre-mix joint compound. ( usually I use the pre-mix 5 gallon...lazy and it's less mess) You can lay poly down under the unit prior to doing the final install as this will prevent any moisture issues while this is drying.

When this sets up, usually with 24-48 hours, your underside will be rock solid supported extremely well!

This does 2 things, prevents any possibility of potential cracking within the fiberglass/acrylic and eliminates any movement (even with the lighter steel tubs) at the drain assembly or potential leaks that could happen.

If you have foam bottom, place the joint compound or mortar in locations so the feet are touching the subfloor. The idea is to drop the unit in, on top of this and not make any adjustments that require you to lift it up to creat air pockets. Doing so defeats the whole purpose.

Hope this helps!

The foam base actually supports the entire bottom of the tub. It is actually a footprint of the tub bottom. The foam base is very ridgid and is glued (i assume) to the bottom of the tub. It is already sloped to ensure proper drainage. Kind of cool actually. This is a Jason forma* AirMassuer tub

I just called the manufacturer and they stated that as long as my subfloor is level (I need to check) then there is no need for a mortar bed. Simply lay some liquid nails down below the foam base to adhere it to the subfloor.

thanks again.