Underfloor heating technology is now sufficiently advanced to not only equal, but exceed the cost-effectiveness and efficiency of traditional alternatives, writes Matthew Miller of Polypipe Terrain. It's simple to specify, easy to install and offers proven performance and flexibility, yet some people remain unconvinced about its suitability for use on applications ranging from schools, industrial buildings and offices through to healthcare and residential properties.
The reasons for this often lies with the different types of construction techniques, which is strange when you understand UFH can be used on virtually any floor structure. It can also be installed during new-build or refurbishment work.

So how does UFH integrate with different types of floors?

For a smaller, solid floor room that needs a higher density of pipe, a UFH panel system is ideal. Floor and edge insulation is first installed and castellated panels laid on top. The castellations ensure accurate installation of the piping and hold it in place while the screed is added. The panels also hold the pipe above the insulation and ensure full screed surround. Clip or staple systems also offer cost-effective installation methods for a solid floor. The floor and edge insulation is covered with a moisture barrier and the pipework is then secured to the insulation with anchor clips, or staples. Where the floor contains a structural mesh grid the pipework can be attached directly to this, either using cable ties or clips. A variety of methods can be used for suspended floors.

The pipe can be laid along the joists using double heat-spreader plates, or across joists on battens using single heat-spreader plates. Where joist centres are 350 mm to 450 mm, double heat-spreader plates can be used to span the gaps and support the pipe at 250 mm centres. These plates run along the joists and allow any return bends to cross joists through pre-prepared notches.

Both acoustic timber batten and cradle and batten flooring pose their own questions about integrating underfloor heating. Bespoke foiled insulation panels spanning the timber battens and including pre-routed pipe runs are an effective answer which combines insulation with effective heat dispersion.

A UFH system is ideal for floating floors above existing timber or solid sub-base constructions. This incorporates a high density polystyrene insulation panel which features preformed pipe grooves at 300mm centres. The pipe is simply pressed into a preformed heat spreader plate which sits in grooves in the insulation panel, before a layer of chipboard sheeting is added.

Limited headroom

Even projects with limited headroom can be accommodated by UFH. Low profile panels can be laid over existing solid or timber floors and glued together, while pre-formed plastic bends are placed at opposite ends of the room. A 12mm pipe is then laid into the grooves and connected back to the manifold. Again, tile, laminate, carpet or vinyl floor covering can be added.

Irrespective of the floor construction, a properly designed UFH system should create a comfortable floor temperature of around 26ºC, throughout a room. This ability to distribute the heat evenly also gives UFH systems environmental benefits, making them compatible with modern low temperature heat sources such as ground-source heat pumps.

Fortunately, consultants, specifiers and installers are increasingly recognising the benefits of UFH and the variety of projects to which it is suited.

The key to a successful installation lies with having sufficient knowledge of how to integrate UFH into the floor construction and the system manufacturer should always be the first port of call for advice on this. Many will assist with every aspect of a project, from initial design through to installation. Always choose a manufacturer who is a member of the Underfloor Heating Manufacturers Association (UHMA), as you'll be dealing with a credible supplier who can help you avoid problems from an early stage.