Loss of heat through floors on concrete surface beds is experienced as a cold underfoot condition, particularly during winter when the supporting soils cool due to hygroscopic action of water. In order that rooms are heated or cooled energy efficiently, the floors need to be insulated from the surrounding soil bed.
The IsoBoard can be installed either below the screeed above the floor slab, or below the floor slab. As a rule, if planning to have an electric heating system to warm your floor, install IsoBoard below screed, to minimize the volume of concrete to heat, to control heating costs. If planning a solar water heating system, install the IsoBoard below the floor slab, as the slab will gradually release retained heat into the building at night. An insulated floor without any under floor heating can be expected to be warmer than an uninsulated floor by 4 to 5 °C. SANS 10400XA required that all heated floors are insulated to a minimum thermal resistance of 1, i.e. 30mm IsoBoard. Specialized applications of this type wpuld include ice rinks and cold rooms.
Surface bed insulation
- Prepare soil foundation and treat with weed killer and place damp proof course. after cleaning, place IsoBoard panels.
- Jointing between boards should be effected with the tongue and groove or shiplap edge profiles.
- The reinforced concrete slab is poured above the isoBoard, in accordance with the specifications of the structural Engineer, with the reinforcing spaced above the board.
- Care must be exercised to prevent board flotation during pouring.
- isoBoard is installed vertically against the inner or outer foundation wall to a depth of 600mm, with the tongue towards the top. Secure IsoBoard with soil ballast