The insulation in our roof may look all yellow and fluffy, which is exactly the way insulation is supposed to look, but on closer inspection there are some gaps.
Our very own CSIRO says that a gap as small as 5% in the insulation layer will reduce its efficiency by over 50%. By my quick sums we have an efficiency of somewhere around minus 300% which is quite a staggering thought really and goes a long way towards explaining why, given the right conditions inside the house can become quite uncomfortably warmer than outside.
If there's anything worse than being of large frame in a confined space, it's being of large frame in a confined space full of dust when the space is inside a roof and the temperature is unpleasantly warm, cutting up bits of fibreglass insulation while the next ten year's quota of perspiration does it's best to ensure that the little shards of fibreglass stick to any exposed skin and work their itchy way below the surface.
Perhaps that's why when the insulation was installed in our place they got out as quickly as they could without actually doing anything particularly useful with the fibreglass batts apart from storing them in the ceiling for convenience of some future owner.
It's all a bit of a shame really, because having decided that one of us would need to fix the problem, every time I looked around for a volunteer she'd be off doing some important job and couldn't possibly spend an hour or so doing a fair imitation of pilates in a sauna while lying on a bed of nails.
Realising that there's have to be compromise if we were going to make progress, I started last night, and worked till midnight pretending that it was comfortable, that I was imagining the heat, and the fact that my clothes looked like I'd just been for a swim in them would have been pleasurable if I actually had. The first half is done, and in only took an extra twenty square metres of insulation to fix. I'd do the rest tonight, but I still remember how uncomfortable it was, and I think I'll wait till the rash has gone and the itching has subsided.
We had the western facing windows tinted yesterday too, so ready as we are to thumb our noses at summer, today the cool change arrived.