Tools and Materials Required:

• Measuring tape
• Utility knife
• Mortar mix
• Mixing bucket
• Trowel
• Level
• Drill
• Screws 
• Flange kit 
• Shower drain assembly kit
• PVC pipe and fittings
• Plumber’s putty or silicone sealant
• Screwdriver
• Protective gloves

Step 1: Prepare the Area

1. Clear the Area: Ensure the subfloor is clean, level, and free from debris. Remove any old shower base or flooring material, if necessary.
2. Dry Fit the Shower Base: Place the shower base into position to verify it fits properly. Check that the drain hole in the base aligns with the drainpipe in the floor.
   
   

   • Mark the Position: Once aligned, mark the outline of the shower base on the floor using a pencil. This will guide you when laying the mortar bed.

Step 2: Create the Mortar Bed

1. Mix the Mortar: Follow the manufacturer’s instructions for mixing the mortar. Use a mixing bucket and stir the mortar until it reaches a thick, peanut butter-like consistency.
2. Spread the Mortar: Apply the mortar within the marked area on the subfloor. Use a trowel to spread it evenly, ensuring full coverage beneath where the shower base will sit.
   
   

   • Build Up the Center: Add slightly more mortar toward the center of the area to support the base's middle section. The goal is for the shower base to sit evenly once placed.
3. Check for Level: As you spread the mortar, use a spirit level to check that the surface is even. This will help prevent pooling water in your shower.

Step 3: Install the Shower Base

1. Set the Base in Place: Carefully lower the shower base onto the mortar bed. Wiggle the base slightly to ensure it settles into the mortar for a solid fit.
2. Check Level: Immediately use a spirit level to check if the base is level in all directions. Adjust as necessary by pressing down on the high spots.
3. Let the Mortar Cure: Allow the mortar to cure for at least 24 hours before proceeding. Follow the manufacturer's instructions regarding curing times.

Step 4: Install the Drain

1. Install the Drain Flange: Attach the drain flange to the shower base’s drain opening, following the instructions provided with the drain assembly kit.
2. Apply Plumber’s Putty: Roll plumber’s putty into a thin rope and place it around the underside of the drain flange. Press the flange into the drain hole of the shower base, ensuring a watertight seal.
3. Secure the Drain: From below the shower base, screw the drain body into the flange, tightening it securely. Use a wrench if necessary, but avoid over-tightening, which can damage the drain assembly.
4. Connect the Drain Pipe: Align the PVC drain pipe with the shower drain and attach the fitting. Use PVC cement to secure the connection if required.

Step 5: Install the Shower Base Flanges

1. Attach the Flanges: Flanges should fit along the outer edges of the base where it meets the walls.
   
   

   • Position the Flanges: Align the flange with the edge of the shower base. Secure it to the wall studs using stainless steel screws.
2. Drill Pilot Holes: If the base does not have pre-drilled holes, drill pilot holes into the flange and base to prevent cracking.
3. Seal the Flanges: Apply silicone sealant along the seams where the flanges meet the walls to prevent any potential leaks.

Step 6: Final Checks

1. Verify Drain and Flange Connections: Ensure all connections are secure and watertight. Check for any gaps or loose fittings.
2. Test for Leaks: Once everything is in place and the mortar has cured, test the drain by running water into the shower base. Watch for any signs of leaks around the drain or flange connections.
3. Apply Wall Panels or Tile: If you're adding tile or wall panels, install them after the base is fully set, using the flanges for alignment.
   

Shower base Installation Video