Recommended Add-Ons
At a Glance
Why Choose This Product
Eliminates cutting and folding membrane at 90° transitions
Fits inward-facing wall-to-wall and wall-to-floor transitions
Protects outward-facing changes of plane
Integrates with GURU Water-Stop waterproofing membrane
Installs over properly prepared plywood or concrete
Includes two matching waterproofing corners per package
Product Information
GURU® Water-Stop Corners provide pre-formed waterproofing for 90° corner transitions in showers and other wet areas. They connect with GURU Water-Stop membrane to maintain continuous waterproofing at corners without cutting and folding flat membrane material.
Inside corners are shaped for inward-facing wall-to-wall and wall-to-floor transitions. Outside corners fit outward-facing 90° transitions. Both configurations provide a clean, consistent fit that simplifies waterproofing at critical changes of plane before tile installation.
Install the shower waterproofing corners with thin-set mortar over properly prepared plywood or concrete. Their 20 mil construction integrates with the surrounding Water-Stop membrane for consistent waterproofing. Inside and outside corners are available as separate options, with two matching corners included in each package.
Common Questions
GURU Water-Stop Corners are pre-formed waterproofing accessories used to seal 90-degree inside and outside corner transitions. They reinforce change-of-plane areas in showers and other wet-area installations, helping connect the surrounding Water-Stop membrane into a continuous waterproof assembly before tile is installed.
Inside corners are shaped for inward-facing 90-degree transitions, such as wall-to-wall or wall-to-floor connections. Outside corners are shaped for outward-facing transitions. Choose the configuration that matches the corner being waterproofed so the accessory lays flat without cutting or field-folding the membrane.
These waterproofing corners are designed to work with GURU Water-Stop membrane and related W-S waterproofing components. Their matching 20 mil construction creates a consistent transition between the pre-formed corner and surrounding membrane, helping maintain waterproofing continuity throughout the shower or wet-area assembly.
Install Water-Stop Corners with thin-set mortar over a properly prepared plywood or concrete substrate. Fully embed the corner into the mortar, smooth the material flat, and remove trapped air or excess mortar. Complete the surrounding membrane overlaps according to the GURU installation instructions.
No. The pre-formed shape eliminates the need to cut and fold flat waterproofing membrane at a 90-degree corner. Select the correct inside or outside configuration, embed it into thin-set mortar, and connect it to the surrounding Water-Stop membrane according to the installation instructions.
Each package contains two pre-formed corners in the selected configuration. Inside and outside corners are separate product options, so choose the version that matches the transitions in the project. Larger showers or wet areas may require multiple packages to complete every corner.
The technical data reports passing waterproofness under ASTM D4068 and a 0.3 perm rating under ASTM E96 Procedure E. Water-Stop Corners reference ANSI A118.10 and ANSI A118.12 and are IAPMO listed under product file numbers 9205 and 9990 for specified waterproofing assemblies.
