This week the structural flooring is being installed. As all new homes are now required to be built to be 5-Star energy compliant, we have opted to use 'concertina foil batt' insulation to the sub-floor space. I chose this product as it achieves a high insulation level (R2.2), it has drain holes to disperse any condensation and unlike many other insulation products, it satisfies the building code requirement for sub-floor ventilation.
The concertina batt is installed close to the bottom of the floor joist. This air gap between the under side of the flooring and the face of the batt serves as an insulating barrier. As our floor joist are deeper than standard joists our resultant insulating R-value would actually be better than the manufacturer's stated R2.2
The purpose of the concertina shape is to provide a greater surface area which dramatically improves the performance of the insulation.
Floor under construction.
Flooring almost complete. As opposed to footing stage, houses always look enormous when there is only a floor to be seen. They then look small when they are framed and large again when plastered. It is generally a cyclic panic that people go through as their homes are being built. "It's too small.....It's too big.....It's too small............oh, that's OK.
Let's not forget the important things.