The Beattie Passive thermal envelope is created by filling the walls, roof and floor with a continuous blanket of insulation. Polystyrene microbeads were pumped under pressure, flowing like a liquid to fill all the voids. The beads were mixed with adhesive during injection, setting them into a solid mass once in position.
The insulation contractors were delayed in arriving so we took delivery of the microbead in these 2 cubic metre bales off the back of an enormous HGV.
Even this quantity (34 bales) was insufficient to fill all of the voids in our house - a second delivery of 18 bales was needed.
Sean and Ross from Evolve Home Energy Solutions set to work pumping the microbead.
It was a noisy process (with the compressor running continuously) and a little messy as some bead was unavoidably spilled on changing over the bales.
Holes were drilled through the Magply lining of the walls / ceiling and through the OSB floor. Microbead was then pumped into every hole - the operators judged when each section was filled by the change in tone of the compressor. It took them 4 days to fill the house.
During the second delivery of microbead, there was an attempted hijacking of the delivery lorry when it was parked up overnight - the canopy was slashed and one of the bales ruptured. So when we unloaded, flurries of bead were blowing down the road as we tried to salvage as much as we could.
It was impossible to sweep up and blew for about half a mile down Yaxham Road.
With the insulation in place, the Beattie boys were able to finish inside. The walls and ceiling were covered in Intello membrane with a lot of care taken to tape the joints in preparation for the airtightness test. Battens were installed ready for our choice of wall / ceiling linings.
The floors were covered with 25 mm of polystyrene insulation and finished with tongue-and-groove boards.
Although we still have polythene sheets covering the window and door apertures, the house feels less echo-ey with these finishes and the insulation in place. We have also noticed during the heatwave this week that the house remained cool inside.