This CPD, in association with Knauf, focuses on the problems arising in moisture-laden environments. By Paul Midgley.
High-moisture settings such as wet rooms, swimming pools and bathrooms present significant challenges for construction materials.
What you will learn in this CPD
- Challenges in high-moisture settings
- Regulations relevant to products used in these environments
- How Knauf’s AQUAPANEL® cement board addresses these challenges
Exposure to constant humidity, water and, in some cases, chlorine can compromise structural integrity, lead to mould growth and escalate maintenance costs.
Builders and designers are tasked with meeting these issues while adhering to strict building regulations and ensuring long-term performance.
The challenge
Designing and building in spaces consistently exposed to water and humidity requires materials that resist degradation and maintain structural integrity over time. Traditional construction materials like gypsum boards or wood often struggle in these environments. Problems such as swelling, warping and mould growth not only affect the building’s durability but can also pose significant health risks.
Commercial settings such as swimming pools can worsen these challenges due to their large-scale exposure to water, humidity and, in certain circumstances, chlorine. Similarly, residential bathrooms with power showers require materials that can handle high levels of moisture without frequent repairs.
Addressing these issues while remaining compliant with industry standards is critical for ensuring well-functioning facilities.
Meeting regulations
There are several standards and guidelines in the UK that products must meet to ensure that materials used in wet environments perform reliably. These include:
- EN 13501-1:2018: This standard provides the reaction to fire classification procedure for all construction products, including products incorporated within building elements (except for power, control and communication cables, which are covered by EN 13501-6). The standard’s parameters evaluate ignitability, flame spread, heat release, smoke production and propensity for producing flaming droplets or particles.
- EN 12467:2012+A2:2018: This standard specifies the performance requirements and test methods for fibre-cement flat sheets, including resistance to bending, frost and moisture. Compliance with this standard ensures durability in challenging conditions.
- NHBC Technical Guidance Update 9.2/06: This technical guidance from the National House Building Council (NHBC) outlines the requirements for residential constructions to gain an NHBC warranty. It ensures materials are suitable when used in bathroom environments with or without power showers.
Materials used in wet environments must meet the above standards and guidance to ensure safety, durability and compliance with best practices.
Knauf’s AQUAPANEL® cement board
Knauf’s AQUAPANEL® Cement Board Indoor addresses the challenges described above by providing a durable, water-resistant solution designed to withstand these challenging conditions. It has been engineered to address the specific demands of moisture-laden spaces.
The board is compliant with EN 13501-1, EN 12467 and NHBC guidance and is suitable for residential and commercial projects. During EN 13501-1 tests it achieved A1 fire classification, which means it is completely non-combustible.
The board also has high resistance to impact and wear. Its lightweight design (11kg/sq m) makes it easy to handle and install, reducing structural load while maintaining high robustness.
The AQUAPANEL® board accommodates curved designs thanks to its maximum bending radius of 1m. Its ability to support heavy tiling (up to 50kg/sq m with standard methods or 120kg/sq m with specific build-ups) makes it versatile as well.
Useful resources
The score-and-snap cutting method simplifies installation, eliminating pre-drilling and reducing dust on site. Additionally, its 12.5mm thickness makes it easy to align with UK plasterboards, removing the need for packers and streamlining transitions.
The board is made from inorganic materials – chemical compounds that contain no carbon – and is not affected by water. Unlike gypsum boards or wood, it does not swell, deteriorate or lose integrity when exposed to moisture, making it a suitable option for wet rooms, bathrooms and swimming pools.
It is also resistant to mould growth, which helps ensure hygiene and health in damp environments. This is an essential measure in spaces such as residential bathrooms, where prolonged exposure to moisture can
promote mould formation.
Paul Midgley is a product owner at Knauf.
Bowmer + Kirkland’s school project
Knauf worked with Bowmer + Kirkland during the construction of the West Coventry Academy, one of the UK government’s flagship net zero carbon in operation schools.
The £38m rebuild project included a new school building, sports centre and outdoor sports pitches.
Among the most challenging parts of the project were the swimming pool facilities. These environments required materials that could withstand these conditions over the long term without warping or deteriorating.
Bowmer + Kirkland approached Knauf for its product range, including the AQUAPANEL® Cement Board Indoor and performance plasterboard, which were installed on a timber frame.
The AQUAPANEL® board maintained its structural integrity despite continuous exposure to water and chlorinated air. It remained durable and resisted mechanical impacts, ensuring long-term performance in high-traffic areas.
Because the AQUAPANEL® board meets the EN 12467 standard, it also fulfilled both regulatory and project-specific requirements.
Architect Gavin Dungan of Stride Treglown said: “AQUAPANEL® performed incredibly well in high-moisture areas. Its excellent dimensional stability and water resistance ensure durability and reduce maintenance costs.”
CPD Module Content
Information in this CPD was correct at the date of publication.
