Step-by-Step Guide: How To Successfully Install the Kerdi Membrane

When it comes to bathroom waterproofing, the Schluter®-KERDI membrane stands out as one of the most reliable solutions available. Its pliable sheet-applied design, coupled with its effectiveness in preventing water damage, mould, and mildew, makes it a preferred choice for both professionals and DIY enthusiasts. In this comprehensive guide, we'll walk you through the process of installing the Kerdi membrane to ensure a successful and watertight bathroom.

The KERDI membrane is a versatile sheet-applied waterproofing and vapor-retardant membrane designed for direct tile application. Its core is composed of modified polyethylene (PEVA), and it features a non-woven polypropylene surface on both sides. The anchoring fleece on these surfaces secures the membrane in thin-set mortar, forming a robust bond that guarantees effective waterproofing. Also, this membrane's uniform thickness of 8 mils ensures consistent performance.


Why Choose the Kerdi Membrane for Your Bathroom?

Waterproofing Excellence

The primary reason for Kerdi's popularity is its ability to prevent water infiltration. Its seamless application ensures that no moisture seeps through, eliminating the risk of structural damage and mould growth behind walls.


Additionally, Kerdi's suitability for various wet areas, such as tiled showers, bathtub surrounds, and residential steam showers, makes it a versatile solution for any bathroom project. Its adaptability to diverse environments highlights its ability to seamlessly integrate with your design aspirations while guaranteeing uncompromised waterproofing.

Ease of Installation

Don't let the prospect of waterproofing intimidate you. The Kerdi membrane is perfect for all levels of expertise, hether you're a seasoned professional or a passionate DIY enthusiast. Its pliable nature makes it a breeze to work with, adapting effortlessly to corners, curves, and crevices.


In a world where consistency matters, the Kerdi membrane shines as a paragon of reliability. Its consistent thickness of 8 mils ensures that every inch is fortified with the same unwavering protection. This uniformity isn't just about aesthetics, it's about trust. The Kerdi membrane's reliability has been proven time and time again, standing as a dependable defence against water and moisture.

Did you know you can get the best possible prices on Kerdi Membranes at GTD Supply? We'll beat any written offer. Find your perfect Kerdi product today!


Step-by-Step Kerdi Membrane Installation Guide

Please note that this guide is intended as an overview. Always refer to the manufacturer's installation instructions for precise details.

Step 1: Prepare the Substrate

Ensure the substrate, usually cement board, is clean and free of contaminants before applying the membrane. Have everything you'll need for the installation nearby as you proceed. 

Step 2: Cut and Layout the Kerdi Membrane

Using scissors or a utility knife, cut the Kerdi membrane to the required size. It's recommended that the membrane extends from the floor to at least the height of the showerhead. Lay out the membrane, ensuring any seams have a minimum 2-inch overlap.

Step 3: Apply Thin-Set Mortar

Using a 1/4” x 3/16” V-notch trowel, apply thin-set mortar to the substrate. Ensure even coverage and make sure to follow the manufacturer's recommendations for mortar selection.

Step 4: Embed the Membrane

Press the Kerdi membrane into the thin-set mortar with firm, even pressure. Use a flat side of a trowel or putty knife to press the Kerdi sheet-applied waterproofing membrane down, removing any air bubbles and ensuring full coverage.

Step 5: Repeat for All Walls

Continue applying the Kerdi membrane to all the walls that require waterproofing, following the same steps for each section.

Step 6: Waterproof Joints and Seams

Use Kerdi-Band waterproofing strips to seal joints, corners, and edges. Apply thin-set mortar, comb additional mortar using the notched side of the trowel, and embed the Kerdi-Band into the mortar.

Step 7: Allow Drying Time

Give the thin-set mortar time to dry, usually around 24 hours, before proceeding to tile installation. This prevents disturbance of the Kerdi membrane during tile adjustments.


By following these steps, you'll be well on your way to successfully installing the Schluter®-KERDI membrane in your bathroom. Remember, proper installation ensures a watertight and mould-free environment, providing you with the peace of mind you deserve.

For further detailed instructions and to ensure the best results, always refer to the official Schluter®-KERDI installation guide. Elevate your bathroom's waterproofing with the dependable protection of the Kerdi membrane from GTD Supply.