wrote in message
ups.com...
I guess this is a tough one....
I am thinking of make the most of two roof windows by letting the light
coming from these through the ceiling into the second floor of a
terrace house.

At the moment I am considering using sheets of polycarbonate
(triplewall 16mm) in the area just below the two windows. These sheets
would cover an area of about 2m x 4m around the centre of the loft
space while the rest will be covered with the usual chipboard.
Ideally, the loft area should be usable...in the same way as if it was
covered entirely by chipboard.
I've already done a quick test and I am quite positive that the
polycarbonate sheet will work just fine if not better than chipboard.

I've used 16mm triple wall polycarbonate for a conservatory roof. I took
great care not to put too much weight on it because I am quite positive it
isn't strong enough. If it were solid 16mm polycarbonate, that would be a
different matter. The more usual material for clear floors is thick glass.

Colin Bignell