Joisted Floor Systems

Underfloor heating for suspended timber floors

Upstairs rooms and older ground floors are often built on timber joists rather than concrete. Underfloor heating still works well on these floors. Because there's no screed to hold and spread the heat, the system relies on boards or plates to carry it across the floor.

Grooved chipboard panels. MaxHeatChip is a 22mm structural chipboard floor with the pipe channels already routed. Laid over the joists, it becomes the floor deck and the heating layer in one. A 6mm foil-backed fibre top board gives a smooth, stable surface for the finish.

Aluminium spreader plates. Where the existing floorboards stay, aluminium heat diffuser plates fit between or over the joists to hold the pipe and spread heat evenly across the underside of the floor. Fit-from-below double plates can be installed from the room below when the floor above can't be lifted.

Insulate between the joists. Insulation below the plates or panels stops heat going down into the ceiling void.

Our floor systems guide and guide to UFH in every room explain how joisted systems compare with screed and overlay floors.