Complying with legislation to create future-proof, carbon-neutral buildings is key. Andrew Watkins of wedi Systems explores sustainable, long-lasting solutions for bathroom and wet room design amid evolving regulations. Andrew Watkins, Technical Manager at wedi Systems (UK) Ltd, discusses how to best comply with new and emerging legislations when it comes to bathroom and wet room design.
Ensuring compliance with current and future legislation, making buildings future-proof and carbon-neutral is a key concern for architects and clients today. Innovative solutions that last the lifetime of the building and reduce the pressure on the planet are now taking centre stage. However, these are not always new technologies or products – while some solutions directly tackle specific challenges, others are more systemic, helping to create the conditions under which all other solutions can be adopted at a greater scale and pace.
Protecting the fabric of the building with reliable waterproofing has always been vital, but now, NHBC’s Technical Guidance 9.2/06 ‘Substrates for tiling bath and shower enclosures, wet rooms and bathroom pods’
reinforces this. In essence, any new home whose foundations begin on or after 1 January 2025 in the UK, must comply with this guidance if an NHBC warranty is to be provided.
In short, magnesium oxide boards must not be used, and in wet rooms or bathrooms with power showers, there are strict requirements; only building boards that hold technical approvals acceptable by NHBC can be used. Critically, whatever the subsurface, all tanking solutions must have appropriate third party certificates such as a European Technical Assessment (ETA) and the tile, adhesive and grout should be compatible with the selected waterproofing system.
There is an obvious advantage of using directly tileable waterproof building boards as opposed to non-waterproof or only water-resistant boards that need tanking. But of course, providing that they hold the appropriate third party certificates, other waterproofing solutions, such as liquid or membrane applied, are also acceptable. However, time is usually of the essence and so it is important to note that not only is research required to ensure compatibility with the chosen substrate and with everything else applied on top of the waterproofing layer, but due to several curing times (priming then sealing with a potential requirement for multiple coats), installation is considerably longer when compared to using waterproof building boards that are directly tileable.
It is also important to consider that liquid and membrane type waterproofing can also restrict the surface design because, regardless of the substrate, the tanking solution determines whether large-format, heavier tiles, slabs or natural stone can be used for example. Naturally, with waterproof building boards, the weight-load capability is a given. In some cases this could be over 100 kg/m2 that gives a freedom of design without drawbacks – e.g. no need to choose between a large, floating washstand and the natural stone finish of the wall.
In 2025, compliance with the Future Homes Standard will also become mandatory; all new homes built from this year are to be future-proofed with world-leading levels of energy efficiency. Low carbon heating encouraged to reduce emissions to 70-80% less than previously accepted.
While directly tileable waterproof building boards may not directly tackle such challenges, thanks to the low U-value, they also contribute to the thermal insulation of the room from the inside, and therefore to the energy efficiency of the home – this makes them perfect to use beneath under-tile-heating (UTH) systems of all kinds. It is also worth mentioning, that some manufacturers offer these boards with factory-cut, precise grooves that not only greatly reduce the risk of the pipe runs being accidentally damaged but also ensure the even placement as close to the surface as possible – ideal to use with heat pump operated water-heating systems under the floor or behind the wall.
Directly tileable XPS boards and shower formers hold all required certificates to comply with NHBC’s new guidance; from Environmental Product Declarations (EPD) and an A+ VOC label, through BBA certificates and a European Technical Approval (ETA) marked to EAD 030437-00-0503, to CE, UKCA and UKNI marks.
It is also worth noting, that using waterproof building boards together with clever accessories and interlocking components – such as floor-level shower elements, benches, niches and ready-to-use partition walls – provides a floor-to-ceiling, systemised waterproofing solution that, when installed correctly, lasts the lifetime of the building.
Finding a manufacturer who, besides directly tileable waterproof elements, can also provide compatible grouts and adhesives that fulfil the above discussed requirements, is not at all impossible. Imagine; everything beneath the tiles from a single source – one manufacturer means one responsibility and of course, one point of contact for planning, construction and for any issues.
So, ultimately, there are two distinctive routes to comply with NHBC’s new technical guidance. One takes you on a journey of complex research during planning, then requires careful time and personnel management during the construction phase if the project is to be completed on time. While the other offers a quick and straightforward installation with significantly less personnel and installation steps being required, and can minimise the risk of failure; simply put, it creates the conditions under which other solutions can be adopted easier and faster.
The focus is on energy efficient future-proof bathrooms, the importance of which our industry is only just beginning to realise. Now more than ever, it is crucial that we implement complementary innovations together; it can provide far more significant outcomes than implementing them in isolation. Streamline the construction process and stay focused on the design.
Andrew Watkins is technical manager at wedi Systems (UK) Ltd