Set the tub flat on the floor and position a level on top of the tub.
Mortar for bathtub install.
Whether you are installing a regular acrylic bathtub that doubles as a shower unit or a larger two person jacuzzi most bathtubs require a mortar base for the tub to rest on.
It is applied to the substrate with a notched trowel.
For extra waterproofing install a shower pan liner between layers of mortar before laying the shower pan on top.
Thin set dries slowly allowing you to fix and readjust backerboard sheets as needed.
Thinset mortar is your default tile mortar for most indoor and outdoor applications.
It should not be runny but rather stand up on it s own.
Both regular thinset mortar and floor leveling compound are suitable.
The tub should be level in all directions.
With the smooth side of a 1 4 inch notched trowel spread enough mortar for one sheet.
Pour the mortar on the subfloor so that it s a few inches from the drain opening.
Add water and.
Ridge the mortar with the notched side of the trowel.
Thinset tile mortar.
Trial fit the tub in the tub alcove.
If the tub is not level use a floor leveling mortar a form or material suggested by the tub manufacturer to level the floor under the tub.
The mortar conforms to the contours of the tub and when it sets it prevents the tub from moving and supports the weight.
The mortar should be evened out and about 2 inches thick on all sides.
Unless you re installing a cast iron bathtub you are going to need a mortar bed to support your tub base.
Mix the mortar so that it can support the tub.
Screw the shower pan rim into the wall studs using 1 1 4 inch screws through the pre drilled holes.
Custom mortar mix you can make your own mortar if you want to save money.
Unsupported fiberglass and acrylic tubs tend to flex under the weight of water plus bathers which can be bad news in terms of your drain staying connected and the tub base remaining solid and free of cracks.
Use thin set mortar when installing cement backerboard.
Then embed the tub into the mortar.
Thinset tile mortar has a smooth slippery consistency similar to mud.