How to Install a Bathtub in Mortar

Bathtubs today come in a variety of shapes, sizes and purposes. No longer are they the cast iron monsters of yesterday. Cheaper than cast iron, waterproof, and much easier to handle due to the difference in weight, most tubs today are constructed our of light weight fiberglass. This very thing that makes them so desirable - being light weight - also makes them more fragile. Many fiberglass tubs wind up cracking on the bottom, allowing water to leak out. The solution is to provide a solid, non-flexible base by installing the bathtub in mortar.

Things You'll Need

• Mortar
• Plastic
• Level

Instructions

1. Place the tub in the middle of the bathroom. Measure the distance from the underside of the tub at the rear, middle, and drain area of the tub.

2. Spread plastic on the floor where the tub will be placed to prevent moisture from the mortar wicking into the sub-floor.

3. Mix mortar and place it on top of the plastic. Spread the mortar out along the area the tub will sit. Use the measurements from Step One to determine the thickness of the mortar bed, adding one inch to each measurement.

4. Place the tub on top of the mortar and press it into the mortar bed until the bottom of the front skirt of the tub touches the floor.

5. Use a level to level the ends and sides and nail through the flanges into the wall studs to finish supporting the tub.

6. Let the mortar cure for 48 hours before using the tub.

Tips & Warnings

• Mortar can burn the eyes. Wear goggles or glasses when mixing the mortar.