BigWallop wrote:

"Roger" wrote in message
...
Hi All

I'm insulating the roof of my garage conversion with Celotex, between and
below the rafters but I'm having a bit of a job cutting the Celotex
accurately.
Snip
A serrated steak knife is usually a good cutter for this stuff. The steak
knife doesn't create to much dust, but it's always wise to wear some kind of
protection against breathing any kind of dust particles, especially in
confined spaces. It's also a good idea to have a vacuum cleaner running in
the background, even an upright lying on its back, to catch anything that
escapes from around the cut.

An occasional smear of margarine or wax on the blade makes for easier cutting
and less dust.