Underfloor heating is a system that provides both comfort and energy efficiency by spreading heat evenly from the floor. Clean walls without radiators and a warm floor make it a popular choice, especially in renovated flats. We filmed this video on one of our sites and explained how the system is installed and what we pay attention to.
How does the system work?
With underfloor heating, polystyrene (EPS) insulation boards are first laid on the floor. Heating pipes are laid over these boards at set intervals. Hot water from the combi boiler is distributed to the rooms via a manifold system, and the floor becomes a heater. The pipes are then covered with screed, and the floor finish is laid on top.
Choice of pipe
In our projects we prefer PEX-A quality pipes of about 16–20 mm in diameter. The pipes are laid more closely in areas where more heat is needed and further apart where less is needed. This way the heat distribution in the room can be adjusted to how the space is used.
Perimeter expansion (edge) strip
A detail often overlooked but very important: along the base of the walls in every room, we apply a self-adhesive edge strip about 5 mm thick and 10 cm high. Its purpose is to stop the screed, which expands as it heats up, from pressing against the wall and cracking. Then the polystyrene boards are cut to size and laid, and the pipes are installed.
Manifold planning
In this project we were in a long, single-storey flat, so we used two separate manifolds. If the manifold cannot be placed in the centre of the flat, all the pipes have to come out of a single point. This causes heat to concentrate there and that area to overheat. In long flats, for example, we split a six-circuit system between two manifolds (feeding three from one point and three from the other) to distribute heat more evenly.
Choosing the floor finish
The efficiency of underfloor heating also depends on the finish laid over it. Ceramic tiles and natural stone conduct heat best. If wood flooring is preferred, products stated to be suitable for underfloor heating should be chosen; see engineered wood or laminate flooring.
Frequently asked questions
Can underfloor heating be installed in a renovation?
Yes; but bear in mind that the floor level will rise by a few centimetres, and door and threshold details must be planned accordingly.
Does underfloor heating save energy?
Because it works at a lower water temperature and distributes heat evenly, with proper insulation it is generally more efficient than radiators.
For your plumbing, heating and installation works, explore our construction and implementation service.
