An integrated system prevents problems with wetrooms and showers

By Carl Stokes, Head of Marketing, Schlüter-Systems Ltd

Wetrooms feature more prominently now in residential and commercial architectural design projects than ever before. Therefore it is essential to install them in the most efficient and effective way. This means installing an integrated wetroom solution with CE Marked waterproofing and products that are designed and manufactured to complement each other for a guaranteed, lasting installation.

When it comes to wetroom design and installation, prevention is better than cure.  One of the most frequent problems with wetroom installations or floor-level showers made of tile or stone, is that cracks and debonding can occur within the covering.  Firstly, this ruins the design and aesthetic appearance of the wetroom in an instant.  Secondly, it wastes time and resources resolving the issues , in order to return the room to its desired state.

This problem is extremely common and is easily noticed due to its visibility to the naked eye.  Having said that, the good news is that it is an extremely easy problem to avoid in the first instance, using modern uncoupling methods.


As a worldwide leading product for over 25 years, Schlüter-Ditra 25 is the unsurpassed uncoupling membrane for tile and natural stone installations which, combined with its CE Marked waterproofing capability, has made it the first choice for securing floor coverings within wetrooms for many architects and specifiers looking for a reliable solution.

It goes without saying that tile or natural stone coverings are the essential option within every wetroom design and, therefore, it is also essential to choose the most suitable protection for the application of these types of coverings; thus, preventing damage within the covering from the outset.

Schlüter-Ditra 25 is a polyethylene membrane with a grid structure of square cavities, each cut back in a dovetail configuration and an anchoring fleece laminated to its underside.  The tile adhesive mechanically locks into cut-back indentations on the topside of the matting, eliminating the need for further anchoring mesh.  This mechanical lock of the adhesive in the square cavities means that the adhesive does not adhere to the mat so no direct bond is formed, allowing for independent movement.

The geometry of the patented Schlüter-Ditra 25 allows for the absorption of lateral movement in each direction.  Through its unique two-layer design, Schlüter-Ditra 25 truly separates the substrate and tile or stone covering by creating essential free space between the layers in which the matting can move safely, reacting to the movement of the substrate and surface, independently of each other.

By their very nature, single part and three part mats cannot function in the same way due to the fact they rely on a direct bond with the screed and surface covering.  By definition, these products fail to separate and rely in some instances, on debonding of layers to cope with movement, leading to long term issues with loose tiles, weakened grout joints and ultimately a cracked surface covering.

The waterproofing layer using Schlüter-Ditra 25 for wetrooms and floor-level showers is easily achieved by carefully sealing the mat joints and connections to floors and walls using Schlüter-Kerdi-Keba sealing band and Schlüter-Kerdi-Coll-L sealant adhesive.


Underneath the tiles: problem solved
When it comes to long term success, possible time and cost savings and versatile design options for wetrooms, we recommend an integrated, single-source system: the Schlüter-Wetroom.  It is one thing to be able to see cracks in the wall or floor covering, but it is the damage that you can’t see within the wetroom that often tends to be the most problematic.

Bathrooms are exposed to significant levels of moisture, and poor moisture management can cause leaks, leading to damage in the surrounding structure and the potential for mould growth.  Systems that do not evacuate water efficiently can be problematic so it is important to opt for waterproof, and not just water-resistant, materials.

There are an array of manufacturers that can provide waterproofing products and you may be tempted to ‘mix and match’ these products to save your budget.  However, that method of waterproofing can be extremely detrimental to the success of the overall solution and, as experts, we would always recommend an integrated solution provided by one manufacturer.
Schlüter-Systems can help protect those stunning installations whilst providing a complete solution for a CE marked waterproof floor-level shower area.

The tile and stone covering in the shower area must be sufficiently sloped to allow for appropriate drainage and it should be noted that the flow of the showerhead must be less or equal to the flow rate of the drain.  Falls in the floor gradient should be between 1 in 80 and 1 in 35.  This is easily achieved with the prefabricated levelling and shower tray components which are available with a point drain system or a component linear drain system.


The point drain system, Schlüter-Kerdi-Drain is where the surrounding area falls at four points to a single point where the water flows away.  The linear drain, Schlüter-Kerdi-Line provides contemporary design possibilities with water draining away via a channel length; both are available with modern grate and cover options.

For the ultimate finish with a continued field of tile or natural stone, Schlüter-Kerdi-Line-D was introduced to the range.  This offers a frameless covering support specifically designed for showers made from tile and natural stone.  Where the grate needs to act as a feature, there are a range of stainless steel designs available with an option to include custom engraving.

The linear drainage system, Schlüter-Kerdi-Line has been updated to ensure that it complies with BS EN 1253, providing a constant 50mm water seal and meeting flow requirements in compliance with National House Building Council (NHBC) regulations for offering a complete system solution.  This range is called Schlüter-Kerdi-Line-G2.

Behind the tile and stone covering on the walls is also an essential area to protect. There are a variety of tile backerboards available in the market, but it is important to specify materials that are waterproof not just water resistant, as water ingress can cause serious damage to the fabric of the building or adjacent rooms.  An additional benefit of a waterproof backerboard, such as Schlüter-Kerdi-Board, is that it doesn’t require an additional waterproofing membrane unlike water-resistant alternatives.  This makes the installation of tile or stone much quicker as only the joints need to be sealed using waterproof sealing band Schlüter-Kerdi-Keba and sealant adhesive Schlüter-Kerdi-Coll-L.

Schlüter-Kerdi-Board is also lightweight and environmentally-friendly as it is free from cement or fibreglass reinforcement and still extremely strong supporting weight limits of up to 60kg per square metre.


Adequate ventilation also needs to be considered to minimise condensation within the shower area or wetroom.  Under-surface heating is an extremely beneficial method for ensuring efficient heating and effective moisture management preventing damp, mould and fungus by drying out any residual moisture and providing the ultimate comfort. The uncoupling technology found in Schlüter-Ditra 25 is also a fundamental feature of Schlüter-Ditra-Heat, the electric underfloor or under wall heating system.

This has pertinence since problems are often encountered with under-surface heating due to the material expansion and contraction that can lead to cracks in the tile or stone covering.

That is why using Schlüter-Ditra-Heat /-TB electric heating system can have the added advantage of crack-bridging properties, which relieve stresses that occur between the substrate and covering to prevent movement and debonding, whilst providing comfort and effective moisture management.


Accessibility in wetroom design – providing access for all
A significant amount of time and thought is invested into the design of bathrooms for architectural projects. One design aspect that is important to consider is how our needs may change over time and the accessibility of the bathroom, especially for those with a disability.

This is where barrier-free bathrooms or wetrooms with floor-level showers, easy-access sanitary ware and the provision of seating areas can offer a practical, future-proof solution. It is always advisable to specify ceramic or natural stone tiles with a high slip resistance and with the huge range of tile and stone available today, creating luxurious, stunning, yet safe, slip-resistant surfaces is easily achievable.

As mentioned above, Schlüter-Kerdi-Board is a waterproof, versatile and functional tile-backerboard used to create a rigid and straight substrate for tiling onto. It can also be used in bonded waterproofing assemblies, however, one of the additional features of this multi-functional board, is that it can be used to create quick and easy seating arrangements within a bathroom, shower or wetroom.


Learn more about specifying a watertight wetroom
The RIBA approved CPD seminar Integrated Solutions for Wetrooms with Tile and Stone Coverings covers the key considerations in the design and installation of walk-in shower areas. Enhance and reaffirm your knowledge with this 45 to 60 minute presentation, held at your offices.

Ultimately, an integrated system solution with products that are designed to work together, should be the specifier’s first choice when selecting products to use in shower areas and wetrooms.  This provides the client with a single point of responsibility should any part of the system fail.

Key considerations covered by the CPD seminar include the benefits of an integrated system for wetrooms versus multi-manufacturer combined offerings; how point and linear drains can be hidden or accent the design; the requirements of waterproofing; and how an integrated system offers peace of mind for a complete solution.

Contact us to book a RIBA approved CPD Seminar.  T: 01530 813396
E: training@schlü or visit our website

Schlüter-Systems have dedicated consultants on hand to help with any stage of your specification project. For more information.
T: 01530 813396 E:  or visit

NBS Clauses and BIM Objects for Schlüter-Systems Ltd are available on NBS Plus, National BIM Library and at