Underfloor heating design. Good Information, Great Result!
‘When installing an underfloor heating (UFH) system either in new-build or refurbishment, utilizing the skills of a supply and design company will lead to the most cost-effective and efficient system,’ says Gary Davies, a member of Nu-heat’s Trade Team.
Gary strongly believes that when an installer is prepared for an in-depth conversation at the outset, the team will come up with the right options for the project. ‘If we have detailed information about a job we can be confident that we have provided the best possible solution,’ says Gary, ‘and the installer will know that each element of the heating design has been planned to suit their individual build. The more detail we have to work with the better.’
The ideal scenario is for an enquiry to be received at the earliest stages of a project, enabling the UFH specialist to take into consideration all the relevant factors associated with the installation.
Most installers understand that a property needs good insulation to ensure that the lower temperatures of UFH maintain peak comfort levels in the home. This is easiest to achieve in new-build, but in refurbishment and retrofit situations it is vital to use a design and supply company that will carry out the critical heat loss calculations. This will ensure that existing insulation levels are taken into consideration and the resulting heating design will achieve optimum performance. Details about the size of the rooms, window structure, ceiling height and glazing all help with these calculations.
Understanding the overall project, including timescales, allows the team to offer practical solutions. For example, in a refurbishment project with major time constraints they might suggest a floating floor to avoid the need for screed drying times (1 day per mm for the first 5mm, 2 days for each subsequent mm). Although screed is usually deemed the best option in terms of system output, as the screed acts as a thermal store, a well-designed floating floor system will also offer an excellent result. In general, a floating floor also offers less of a floor height build up as illustrated by two of Nu-Heat’s most popular floor constructions: SC14 with a screed depth of 65 to 70mm in contrast to DPF14 floating floor at 25mm plus chipboard or ply at 18mm.
Where a fast, clean install is required, such as in a renovation with new extension where the building is still occupied, practical solutions can be offered. In this case the answer is likely to be a floating floor or a panel system between joists.
When a project includes first floor underfloor heating and the details suggest that the chipboard or ply deck will be installed upstairs prior to the UFH, the UFH specialist may well suggest the use of a product like Nu-Heat’s ClippaPlate™ system, meaning that other work won’t be interrupted as the UFH can easily be installed from below. Another popular floor construction, TPB 14 – suspended joists, mineral wool insulation, air gap, reflective cellular foil insulation, ClippaPlate ™ diffuser plates (fitted either between or over joists), 14mm tubing and timber floor – meets this requirement perfectly.
However, in a refurbishment scenario where the ceiling is in situ or not being replaced, work must be carried out from above without any floor height build up. In this case, for example, batons can be attached to either side of the joist, followed by ply deck, tracked polystyrene insulation, diffuser plates and finally the UFH pipe that finishes flush with the top of the joist level (floor construction DPJG14).
Where joists are of different sizes, suggestions could include a biscuit screed or floating floor construction. If, however, the staircase has already been installed, a floating floor option may not feasible due to floor height build up.
A design and supply company is only as good as the information it is given. With the right details, the UFH specialist will be able to ‘think outside the box’ and arrive at the best solution for the property.
In one instance, an installer approached Nu-Heat with a fairly challenging refurbishment plus new extension, creating two different floor constructions in one room – on one side new screed and on the other existing timber with irregular centre spacing. To ensure ease of design and installation along with continuity of performance, Nu-Heat advised putting batons into the new screed at the same centre spacings as the existing timber, and using a biscuit screed on the joisted area. This had the added benefit of giving continuity for fixing the new wood flooring.
Finally, there is ethical selling – a concept that Nu-Heat for one is fully behind. ‘If it becomes apparent that UFH is not going to perform,’ says Gary, ‘a reputable design and supply company should tell the installer at the earliest opportunity so insulation levels can be improved or alternative heating systems considered.’