Waterproofing Corners

Waterproofing corners are preformed components designed to seal compatible inside and outside corner transitions in showers and other wet-area tile installations. They integrate with the surrounding waterproofing system to help maintain continuous protection where walls, floors, benches, projections, and other adjoining surfaces meet.

Inside waterproofing corners are designed for internal intersections where adjoining surfaces meet, such as wall-to-wall or wall-to-floor transitions. Outside waterproofing corners fit external transitions and projections. Because the shapes are different, select the corner according to both the transition type and the waterproofing system being installed.

A 90-degree waterproofing corner is designed for compatible right-angle transitions, while a 135-degree corner accommodates wider angled transitions found in certain shower layouts and components. Match the preformed corner to the actual angle of the installation and verify that it is approved for the surrounding waterproofing system.

Many preformed waterproofing corners are designed to integrate with compatible sheet membranes and other waterproofing systems. The corner material, required overlap, and bonding method can vary by manufacturer, so confirm compatibility with the specific membrane and use the manufacturer-approved mortar, sealant, adhesive, or waterproofing material for installation.

Waterproofing corners may be used at wall-to-wall and wall-to-floor intersections, outside projections, benches, curbs, and other compatible changes of plane. The required locations depend on the shower design and waterproofing system, so follow the system manufacturer's requirements when determining which transitions need preformed corner components.

Installation depends on the specific corner and waterproofing system. Preformed corners are typically positioned over the appropriate transition and integrated with adjoining waterproofing materials using the manufacturer-specified bonding method. Follow the product requirements for substrate preparation, bonding material, overlaps, and placement to create the intended waterproof connection.

No. Waterproofing corners can differ in material, dimensions, installation method, and compatibility with membranes, backer boards, and other system components. Do not assume that a corner from one manufacturer is interchangeable with another system simply because the angle and general shape appear similar.

Identify whether the transition is an inside or outside corner, determine the required angle, and then match the corner to the waterproofing system being installed. For benches and unusual transitions, check whether the manufacturer offers a specialty corner designed specifically for that configuration rather than modifying a standard corner.