How to Build a Shower Pan Hot Mop
A hot mop shower pan is a durable and watertight solution for your shower floor. It involves applying a layer of hot asphalt-based waterproofing membrane to a prepared subfloor. This guide will walk you through the process of building a hot mop shower pan.
Important Note: This is a complex project requiring specialized tools and experience. It is recommended to consult a professional contractor for guidance and assistance.
Materials:
- Plywood: 1/2" or 3/4" exterior grade plywood, cut to fit your shower pan dimensions
- Concrete backer board: 1/2" thick, cut to fit your shower pan dimensions
- Waterproof membrane: Hot mop asphalt-based waterproofing membrane
- Flashing: Metal flashing for the shower pan perimeter
- Drainage system: Shower drain and necessary components
- Mortar: Thin-set mortar for setting the concrete backer board
- Primer: Bonding primer for the subfloor and backer board
- Sand: Fine sand for filling gaps and leveling
- Tools: Trowel, putty knife, hot mop kettle, safety gear (gloves, mask, eye protection)
Steps:
1. Prepare the Subfloor:
- Clean: Ensure the subfloor is clean, dry, and free of debris.
- Level: Use a level and sand to level any unevenness.
- Prime: Apply a bonding primer to the subfloor to promote adhesion.
2. Install the Plywood:
- Cut and secure: Cut the plywood to fit the shower pan dimensions and securely attach it to the subfloor using screws.
- Create slope: Create a slight slope towards the drain by adding a thin layer of mortar or shims under the plywood.
3. Install the Drainage System:
- Install drain: Install the shower drain according to manufacturer instructions.
- Ensure slope: Make sure the drain is properly installed and positioned to accommodate the slope you created.
4. Apply the Hot Mop Membrane:
- Heat the membrane: Heat the hot mop membrane using a hot mop kettle according to manufacturer instructions.
- Apply layers: Apply the hot mop membrane in multiple thin layers, ensuring each layer is completely dry before applying the next.
- Create a lip: Extend the hot mop membrane up the walls of the shower pan to create a lip that prevents water from escaping.
5. Install the Flashing:
- Cut and bend: Cut and bend the flashing to create a watertight seal around the perimeter of the shower pan.
- Secure with mortar: Use thin-set mortar to secure the flashing to the shower pan walls and ensure a tight seal.
6. Install the Concrete Backer Board:
- Cut and apply primer: Cut the backer board to fit the shower pan area and apply primer to both the backer board and the hot mop membrane.
- Set with mortar: Use thin-set mortar to set the backer board onto the hot mop membrane, ensuring it is level and aligned with the drain.
7. Finish and Seal:
- Sand: Sand any rough edges or imperfections in the backer board.
- Caulk: Caulk around the perimeter of the backer board and at the junction with the shower walls to prevent water leaks.
Important Considerations:
- Ventilation: Proper ventilation is crucial to prevent moisture buildup during the drying process.
- Safety: Always wear appropriate safety gear when working with hot mop membrane.
- Professional help: Consider seeking professional help for this project, especially if you lack experience.
This guide provides a general overview of building a hot mop shower pan. Remember, proper planning, attention to detail, and adherence to safety guidelines are crucial for a successful outcome.
