Port Willunga – underfloor heating – timber floors

The brief from the client was to incorporate underfloor heating throughout the timber framed house manufactured by Timber Frames of Australia. The floor covering, apart from the wet areas, was to be Messmate which is an Australian grown hardwood also known as Messmate Stringy Bark and the total floor area to be heated was 260m2.

Preparation of the Floor

A two stage pour installation method was chosen to improve the systems operating costs and also to allow the Messmate flooring to be used. The downstairs had a standard concrete slab poured that had hardwood battens fixed to it which served a dual purpose. The battens created a void that allowed insulation panels along with the pipework to be installed, both being covered with a concrete screed that acts as a thermal mass. The battens also allowed a fixing for the hardwood floor to be installed otherwise it would have been hard to install this type of flooring direct onto a concrete slab. All of the wet areas are located on the lower level and they were also insulated before the pipework was installed and a selected concrete screed was laid which was then polished at the end of the build.

Underfloor Heating and Insulation

The upper level consists of half concrete slab construction at the front of the property and timber floor joists at the rear, again hardwood timber battens were installed throughout this level thus allowing a two stage installation method. During the build the timber joist area was sheeted with a flooring product which allowed the building construction to continue. At the appropriate time, timber battens were fixed on top of the joists and also the concrete slab allowing the insulation, pipework and screed to be installed, after a drying out period for the screed, the Messmate was installed.

Heating source

Natural gas is not available at the property so a 23kw air sourced heat pump was installed to provide all the houses heating requirements. The client also over specified the house insulation during the build and went above the Australian building Code guidelines using numerous different insulation products throughout. The additional insulation has allowed the house to retain not only the heat but also the cold introduced into the property therefore reducing running costs in both winter and summer.
The project did throw up some issues but with excellent communication between the timber framing company, the carpenters, the clients and us all problems were overcome.