The first floor underfloor heating has now been fitted. We would often use chipboard flooring on the first floor, but in the Show House we are using a pug screed.

This is a thin biscuit layer of screed. It is often chosen for use with low temperature heat sources such as heat pumps, as it acts as a thermal store and conducts heat more evenly to the surface above. We are using a ground source heat pump which will heat the floor to about 35-45’c.

The screed is for heat conduction purposes only and is mixed fairly dry. It is made of a mix of sand/cement 8:1 dry mix. Any cracking does not affect the thermal performance of the system. You will note that the screed has a much rougher finish compared to the ground floor screed.

The screed is 28mm in depth and flush with the top of the joists for best heat transfer. This ensures that is penetrates fully underneath the underfloor heating pipe and sits level with the top of the batten. As the screed is directly below the covering board, heat conductivity is increased.

Once the screed has been allowed to cure, the ply boards are screwed into the exposed timber battens.