Suspended Floor Construction

Suspended floor construction systems include joisted floors as well as solid floors with battens fixed to the floor.

Aluminium spreader plates are ideal for underfloor heating applications on suspended floor constructions.

The floor void must be insulated with either loose fill insulation, or mineral wool insulation, and it is advised to minimise airflow to reduce the possibility of heat loss.

For irregular joist widths cut the plates to fit.


A wet underfloor heating system can be installed a number of different ways in regards to suspended or joisted floors. As a rule this does normally affect the floor build-up height.

There are 3 main ways to install a UFH system within a joisted floor:

  • From above – if you are working on an open joist void, you can fit the plates from above, to either side of the joists
  • From beneath – sometimes, you can’t fit the plates from above. For example, in an older property where the existing floorboards cannot be taken up.
  • Within the structural floor layer – the wet underfloor heating pipework can be installed within a pre-routed chipboard panel, that can be directly laid over the joists