10 September, 2001

Dear Tim,

When we moved into our home, we were under the impression that we needed to insulate the roof cavity for winter and summer. Due to the renovation plan, the insulation was scheduled to be installed after about 2 years of living in the property.

We froze in winter even though the newly installed hydronic heating was working correctly; delightfully we also froze in two of the hottest summers that I can remember (97 and 98).

The double brick, slate roofed Victorian house remained cool for up to 4 days in heat wave conditions, bearing in mind we had no window furnishings inside or out, no carpet, no ceiling fans, no airconditioning, no external foliage to shade the house and absolutely no ceiling insulation. Sleeping was a breeze and no artificial cooling was required of any kind.

R3 Rockwool insulation was chosen due to noise requirements and for heat and cold insulation properties. Installation took place in Nov 99 and come December’s first hot weather we could not believe how quickly our once cold house would heat up. Natural night time cooling of the house would not take place and heat would radiate downwards from the ceiling regardless of window positions. We could not cool the house down even after one day of 35 degree heat, living conditions became oppressive.

Upon ceiling inspection one early morning the Rockwool was found to be at a temperature substantially above that of the roof cavity and way above ambient temperature. From my findings I deduced that the Rockwool was getting heat soaked throughout the day, somewhere in the order of 70 degrees C. and because it was such a good insulator it retained much of the heat throughout the night, hence the radiator effect at night.

I have since installed 2 large volume thermostatically controlled heat extraction fans on the roof to try and alleviate the heat build up in the roof cavity and thus reduce the heat soak temperature. The fans seem to have made a slight difference, but not what I expected for my $1000.

Needless to say we are most impressed with our insulations performance in the winter months, however during the last summer I wanted to get into the roof and rip my $1200 worth of R3 Rockwool insulation up and dump it at the tip. I want my cold house back for the 2001 summer, how am I going to achieve this without installing airconditioning?

From what I understand from reading the testimonials from satisfied customers who have installed your Concertina Foil Batts, I intend to place the Foil Batts across the top of the existing Rockwool batts. I await the first hot spell so as to gauge the effect.

Yours sincerely,

Philip Schwarz