The desire for the perfect finish is universal, but this can only be achieved by using an absolutely level substrate that is ready to tile. There is an easy way to achieve this, one that is increasing in popularity install after install.
No talk of backerboards can skirt over the significant changes to British Standards in 2018. June 2018 saw a number of important updates to BS 5385 Part 1, covering the design and installation of wall tiling in internal conditions. Amongst these changes was the stipulation that tiling direct to plywood (and other sheets and boards subject to movement from changes in moisture content) is no longer recommended and that a bespoke tiling backerboard should be used in its place. This particular change was prompted by the entry onto the UK market of cheaper plywoods that are not fit for purpose in terms of providing a suitable substrate for tiling. It also gives kudos to the effective solutions that manufacturers within the industry have released to combat the issue.
Other Methods of Waterproofing vs. the Preformed Backerboard
There are two main ways of creating a smooth waterproof substrate for tile and stone: liquid applied or sheet membranes over plasterboard or water-resistant board, and preformed waterproof tile backerboards.
Although liquid-applied membranes are still a popular choice due to their cost-effective nature, they present distinct disadvantages that particularly hamper large-scale projects. They are difficult to apply evenly, meaning areas can be left unprotected and they are often slow to dry making for a protracted project timeline.
Sheet membranes are hung like wallpaper into a bed of adhesive. By their very nature they provide even and visible coverage, but as is also the case with liquid-applied membranes, their use relies on being able to apply them to an even substrate. This means that they are often used over plasterboard or water-resistant backerboards, which can be weighty and cumbersome.
Preformed waterproof tile backerboards simultaneously supply an even substrate and waterproofing capabilities. These boards negate the need for two separate products and therefore two separate installation processes.
A Flexible and Multi-Functional Solution
Schlüter®-KERDI-BOARD is the cement and fibreglass-free, multi-functional installation board, suitable for use in both renovation and new-build projects. Providing a flat and even substrate and enabling precise angling of corners, seven thickness options are available, ranging from 5 to 50mm. While the boards at the thinner end of the spectrum are designed for use over existing substrates, latter thicknesses can be used as construction panels to create features such as shelves, partition walls and seats, allowing for unbridled freedom of design.
Proper moisture management is essential to guaranteeing successful long-term performance. In no area does this ring truer than a wetroom or bathroom. When specifying for these areas, a key point to grasp in order to ensure a finish that is fit for purpose is the difference between waterproof and water-resistant backerboards. Waterproof boards do not allow water to penetrate their surface, whereas water-resistant boards allow water to pass through. This means water-resistant boards alone cannot provide adequate protection for a tile or stone installation; they will always require an overlay with a liquid applied or sheet based waterproofing membrane. With a waterproof backerboard, this additional process is not necessary, saving significant time on-site.
Schlüter®-KERDI-BOARD provides bonded waterproofing, with no need for additional finishing processes. Using the various accessories available from the Schlüter®-KERDI range, the seams between individual boards are quickly and robustly sealed, creating a complete bonded waterproofing assembly for tiling without delay.
Preformed Pieces for Easy Designer Features
As well as the standard boards, a number of other products are available as part of the Schlüter®-KERDI-BOARD family, including Schlüter®-KERDI-BOARD-N, a collection of fully sealed, prefabricated niches for the quick creation of stylish recessed shelves. Design possibilities extend beyond flat planes of construction courtesy of Schlüter®-KERDI-BOARD-V, a grooved version of the board, specifically designed for the purpose of creating curved and rounded features.
For contractors, a move to Schlüter®-KERDI-BOARD allows for a quicker and easier installation process, with time savings being made due to its light weight and ease of cutting.
Environmentally Friendly Composition
Schlüter®-KERDI-BOARD makes for a considerably greener alternative to other options, such as plasterboard and cement-faced products. It is constructed of an extruded hard foam core panel, with a special reinforcement material on both sides and waterproof fleece faces to finish, providing effective anchoring in the tile adhesive. The foam core of Schlüter®-KERDI-BOARD is thermally insulating, helping to conserve energy use and improve comfort. The absence of a cementitious layer means that it costs less to transport and produces no dust when cut, making for healthier working conditions and avoiding release of toxins into the wider environment.
Dependent on the background that it is being installed onto, Schlüter®-KERDI-BOARD is either fully embedded into tile adhesive or screw-mounted. The latter method is used for installation upon professionally constructed stud frames and the areas where the screws attach are easily waterproofed using Schlüter®-KERDI-KEBA sealing bands and Schlüter®-KERDI-COLL adhesive.
Learn More About Specifying Substrates
The importance of specifying waterproof rather than water-resistant backerboards for tile and stone is a key topic covered in our CPD seminar ‘Specifying Integrated Solutions for Waterproofing and Wetroom Systems.’ Enhance and reaffirm your knowledge with this 45 to 60 minute presentation, held at your offices.
This CPD also covers other key considerations for construction of a wetroom that is fully fit for purpose, including: the benefits of integrated systems 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.
For support across all elements of your specification journey – from learning about the fundamentals of tiling systems, through to project-specific advice and detailing – call 01530 813396 or email
Schlüter-Systems Ltd’s specification website is a helpful companion for architects and specifiers tasked with achieving first-class installations of tile and stone; head to www.schluterspecifier.co.uk, where you can also request a VR headset to engage with the company’s 360 Tour of their impressive and educational premises.