How to Level a Bathtub With Mortar

Put a layer of plastic sheeting down on the floor near your work station to protect your mixing area. Cut the plastic sheeting with a utility knife and position your wheelbarrow close to the tub enclosure.

Layer the installation surface under the tub with felt paper and chicken wire. Cut the paper with a knife and the wire with tin snips. Put the felt down first and overlap it a few inches. Cover that in chicken wire, overlap the pieces slightly, then tack everything in place with the hammer tacker.

Mix both bags of mortar in your wheelbarrow. Add water according to the manufacturer's instructions and stir the mixture by shoveling it around in the wheelbarrow. After it is mixed, shovel it in an even layer onto the floor on top of the wire and mesh in the tub enclosure. Cover the mortar in a plastic sheet.

Check the frame of the tub with your level. Add shims where you think the edge of the tub must be held up for level. Maneuver the tub into place and step into the tub gently to push it down into the mortar. Check with your level around the tub rim and add shims where necessary.

Fill the tub with water and let it sit for at least 72 hours. Water is self-leveling, and as long as you installed shims around the edge of the frame (or had a level frame to begin with) the bottom of the tub will self-level with the weight of the water as it simulates the body of a human and a filled tub, contouring the mortar into a solid base.