How to Upgrade Old Drains for a Modern Shower Remodel

In any tiled shower, proper drainage does more than just remove water—it protects the structure, mitigates mold and mildew risk, and ensures a top-tier showering experience. But when working in occupied condos, high-traffic gyms, or spa facilities, even a single day of downtime can hurt revenue and client satisfaction.

KERDI-BOARD_TRENDLINE

Replacing an outdated drain system the traditional way often means demolition, debris, and delays. Fortunately, that doesn’t have to be the case for the drain connection itself. With Schluter’s retrofit adaptor kits, you can modernize your drain setup—without tearing out the existing plumbing connection—saving time, labor, and money.

 Why Modernize Your Drains?

Upgrading the drain is a smart move in both residential and commercial renovations:
  • Efficiency & Reliability: Modern drains require less maintenance than traditional drains
  • Cost & Time Savings: Avoid full drain demolition—cut labor and accelerate timelines
  • Aesthetic Upgrade: Sleek, modern grates elevate the overall shower design
  • Perfect for High-Traffic Spaces: Gyms, condos, hotels, and spas benefit from quick turnaround and durable performance

Understanding Drain Systems: A Quick Comparison

 Clamping Ring Drains

  • Assembly: Multi-piece design with a separate clamping ring and membrane layer
  • Installation: Requires precise alignment and additional components for waterproofing
  • Waterproofing: Relies on a liner clamped between drain components—more parts, more risk
  • Compatibility: May limit integration with bonded waterproofing systems

Integrated Bonding Flange Drains

  • Assembly: Single-piece design with a built-in flange for direct membrane bonding
  • Installation: Streamlined process with fewer steps and materials
  • Waterproofing: Membrane bonds directly to the drain flange for a reliable, sealed connection
  • Compatibility: Fully integrates with modern bonded waterproofing systems like KERDI

Drain Style Considerations: Point vs. Linear

With a retrofit, you don’t just preserve the drain connection—you open the door to new design choices.

Point Drains

  • Installed at a central low point
  • Work well with traditional shower layouts
  • Require a four-way slope in the tile assembly

Linear Drains

  • Installed at one end, in the center, or along a wall
  • Allow for a single-direction slope—ideal for barrier-free or curbless designs
  • Provide a clean, modern look and are compatible with large-format tile

Proven Drain Solutions: KERDI-DRAIN and KERDI-LINE

Once you've decided between a point or linear layout, the next step is choosing a dependable, long-term solution. Two systems stand out: KERDI-DRAIN and KERDI-LINE.

KERDI-DRAIN

  • A point drain with an integrated bonding flange
  • Designed for use the Schluter Shower System and bonded waterproofing membranes
  • Eliminates the need for a secondary seal, reducing potential failure points
  • Offers various grate finishes, including tileable options 

KERDI-LINE

  • A linear drain system ideal for sleek, curbless, or spa-style showers
  • Includes an integrated collar made of KERDI for waterproof connection
  • Compatible with shower entry, center, or wall installation
  • Available with a wide range of grates and finishes, including tileable grates for a seamless tiled floor look

Both drain systems are fully compatible with Schluter retrofit adaptor kits , allowing you to install them over an existing clamping ring-style connection without disturbing the plumbing below. 

Assess Your Existing Drain

Before you can install an adaptor, confirm the existing conditions:

Drain Type : Is it a clamping-ring drain or something else?
Material : PVC, ABS, or cast iron?
Pipe Alignment : Make sure the outlet lines up with your desired Schluter system
Height : Verify finished floor elevation and determine if a compensation board is needed

Retrofit Solutions in Action

When you're ready to move forward with a retrofit, adaptor kits make it possible to transition from a clamping ring drain to a modern system—without disturbing the drainpipe.

 

KERDI-DRAIN-A Adaptor Kit

Converts clamping-ring drains to an integrated bonding flange system.
Available in multiple diameters to fit a wide range of installations.
Features versatile hole patterns to match common bolt configurations.

KERDI-LINE-A Adaptor Kit

Allows for the installation of a linear drain over an existing clamping-ring-style connection.
Precision-engineered gaskets create a watertight seal.
Supports sleek, modern drainage layouts without the need for relocation.

Step-by-Step Retrofit Process

Here’s a typical retrofit workflow using an adaptor kit:

1- Remove Old Components

  • Remove the clamping ring and upper flange
  • Retain existing bolts

2- Install the Adaptor Ring

  • Match and punch out the correct hole pattern
  • Apply a continuous bead of KERDI-FIX to the installed drain flange
  • Secure using original bolts in a star pattern

3- Insert New Drain Body

  • Slide the bonding flange (KERDI-DRAIN)
    or linear channel (KERDI-LINE) into place
  • A precision gasket ensures a leakproof seal

4- Adjust Floor Height & Slope

  • Use a KERDI-SHOWER-CB compensation board (1" or 3½")
    to match new drain height
  • Build slope with a foam tray or mortar bed toward the new drain

5- Apply Waterproofing

  • Embed KERDI membrane to flange using unmodified thin-set
  • Seal all seams with KERDI-BAND and KERDI-KERECK corners
  • Waterproof curb and wall junctions as needed

6- Tile & Finish

  • Tile directly over the membrane
  • Snap in your chosen drain grate or linear drain grate
  • Grout, clean, and you’re done

Finishing Touches: Design & Flexibility

 

Choose from a wide range of finishes:

  • Stainless steel, matte black, TRENDLINE color options, or tileable covers pair with other Schluter elements like profiles and shelves for a cohesive look.

Final Considerations

  • Installation Guidelines & Code Compliance : Always follow Schluter instructions and local plumbing codes to maintain warranty coverage
  • Long-Term Value : Integrated bonding flange drains offer better waterproofing, less maintenance, and a longer service life

Ready to Retrofit?

If you’re looking to upgrade the performance and appearance of your showers—without the time and mess of full drain demolition—Schluter’s adaptor kits are the solution.

Explore our KERDI-DRAIN-A and KERDI-LINE-A systems at schluter.com , or contact our customer service team to find the right fit for your next job.