Wednesday, 1 February 2012

The Zellofant cometh

After a couple of false starts, today was the day the Zellofant came. We spent the best part of six hours together, so I got to know it very well. What is it? A great big masher for Zellulosefaser-Dämmstoff, or cellulose fiber insulation, also known as minced up newspaper. It's an environmentally-friendly material that also happens to be a pretty good thermal and sound insulator. In our case, it has been used to insulate the roof, by blowing it in between the rafters which have been covered with, well, an envelope of brown paper.
The Zellofant.

Bales of cellulose insulation.
The Zellofant feeding.

During the course of the day, 141 bales of compressed cellulose insulation, each weighing 14kg were fed to the Zellofant, which promptly spat them though a hose to the professional up in the roof. By cutting into the paper envelope, he was able to blow in the cellulose insulation, resulting in  200mm thick layer of insulation between the rafters. That, combined with the wood fibre sheets that lie on top of the rafters means our roof is pretty well insulated*.

There's 1974kg of cellulose behind that paper membrane!
This was the last major component of the roof. The rest is just internal finishing (well, we don't fancy looking at brown paper forever), but that can come later. Probably a lot later!

*If you're a interested, the wood fibre boards have a K (thermal conductivity) value of 0.044 W/(m·K) and are 35mm thick, while the cellulose has a K value of 0.04 and is 200mm thick, meaning we should have a total U value of 0.17 for the roof surfaces (if I've understood the formulae correctly!).

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