Insulation upgrades

pumping in wall insulation

Reader stories on how they improved the thermal performance of their homes, while reducing energy bills. By Eva Matthews.

Dennis Kavanagh has been incrementally improving his home in Blackburn, in Melbourne’s east, over the last few years. As well as deciding to go all-electric and installing a 9.8 kW solar PV system on his roof around 11 months ago, Dennis turned his attention to improving the home’s thermal performance through insulation and draughtproofing.

Little existing insulation

After attending a free EnviroGroup presentation run by ecoMaster on these topics, Dennis ordered a premium assessment for his home, which resulted in a number of recommendations and quotations to address them. They identified his ceiling insulation, which had been installed about 40 years ago, as being in reasonable condition but only rated R1.0. There was no insulation in the walls or underfloor. With Dennis unable to “crawl up or into awkward spots” himself, ecoMaster installed the insulation in the roof and underfloor in August 2015, both in the same day. Access to the roof was via the manhole; underfloor access was limited under the bathroom, laundry and some of the third bedroom, so they achieved around 70% coverage there.

For the walls, being brick veneer, Dennis’s best option was to have the insulation pumped in. As this type of application can cause a fire hazard, and the installers ecoMaster recommend require an electrical safety certificate, Dennis organised an inspection prior to the installation, using electricians from EnviroGroup. After checking behind power points and testing at the meterbox, and with Dennis having upgraded his wiring recently, they determined that all was good to go.

In January 2017, one man with a truck of granulated Rockwool (mineral wool) pumped in the insulation in less than a day. Most of the walls were accessible by shifting some tiles on the roof, through which the insulation was pumped in down a flexible hose. Solar panels were in the way in some spots, so not all the walls could be accessed from above; in this case Dennis thinks the insulation may have been pumped across from a neighbouring entry point. Holes were then drilled under the windows to pump into those lower spaces, and a mortar mix used to patch them. Although Dennis was somewhat concerned about whether it would match the existing mortar, he says it worked out well: “Unless you look closely, you don’t even notice it.” Also, batts were put in to fill gaps between the top of the timber wall framing and roof.

Read the full article, with two other case studies, in ReNew 140.