Tiled floors with underfloor heating: A guide to minimising and repairing cracking
BRE (Building Research Establishment) is an independent, research-based consultancy, testing and training organisation, operating in the built environment and associated industries.
On 22 May 2015, BRE published Tiled floors with underfloor heating: A guide to minimising and repairing cracking (IP 6/15), by Rupert Pool and Tony Yates.
Warm-water underfloor heating (UFH) has become more widely used in the last 10–15 years. It provides background heat in large spaces and makes tiled floors much more comfortable to walk on in houses. Compared with traditional radiators, UFH provides a number of operational benefits because of the lower temperature of the circulating water. This can improve the efficiency of the boiler supplying the heat and allows the use of renewable energy sources such as ground source heat pumps.
However, cracking, associated with underfloor heating is a common cause of problems in rigid tiled flooring. BRE has investigated many cases where stone or ceramic tiles have been laid on screed only for cracks to appear in the tiles and along grouted joints within weeks of the heating system being operated. This is almost always caused by movement of the screed at a pre-existing crack or, in some instances, a ‘day’ joint in the screed. Even though this movement is just a fraction of a millimetre, it is sufficient to crack thick granite slabs. These cracks are normally the result of a poorly-designed floor screed (ie badly coordinated movement joints) or failure to properly commission the heating system before the tiles are laid.
This 8-page information paper sets out BRE’s experience of screeds that contain warm-water underfloor heating systems and describes how the risk of cracking can be minimised and how repairs can be undertaken. It is intended for architects and specifiers.
Its contents are:
- Introduction.
- Description of underfloor heating systems.
- Screed.
- Design of screed to incorporate underfloor heating.
- Problems that can occur.
- Crack-isolation systems.
- Commissioning the heating system.
- Checking a screed before the tiles are laid.
- Conclusions.
- References.
- Further reading.
Electric ‘undertile’ heating and proprietary ‘thin-screed’ underfloor heating systems are not dealt with.
[edit] Find out more.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Paul Morrell to lead independent review of the construction products testing regime.
Standard will help employers foster wellbeing and manage psychosocial risks.
The United Nations has approved the IFSS common principles
Global fire standards for safety of people and property.
An introduction to the 5 core principles of lean.
Civil engineers and environmental methods of construction
Can the profession use its skills to save the world from climate change?
How faulty science resulted in sanitation reform.
Conserving the Hilda Besse Building
Improving facilities, accessibility and overall appearance.
BSRIA IAQ topic guide published
Free download of TG 12/2021 available.
Electrotechincal mentors wanted
TESP works with The Youth Group to form skill sharing network.
OpenBuilt supply chain technology in development
Big tech collaborates on platform for the built environment.
Concerns raised over Future Buildings Standard
Letter signed by 21 organisations sent to MHCLG.
The infrastructure planning process
A look at the Government's strategic approach.
Steps to help reduce the spread of infection inside buildings.
Urban exploration and construction
This social media-centred hobby can be both dangerous and illegal.
Receive the Designing Buildings newsletter
Click the button to subscribe.