"Christian McArdle" wrote in message .net...
If a natural slate roof is unfelted, does this provide any ventilation to
the underside?

Lots. And water as well.

I'd like to jam some celotex between the rafters, but won't
be bothered if I need to install specific ventilation at eaves and ridge.
The roof covering will probably be replaced in the next five years, when
felt and specific ventilation can be added. I just want to still have the
rafters in one piece when this happens.

If the insulation dries out quickly OK, but if its so dense that it
dosent, I wouldnt. Unlined slate roofs do let in water, then the air
comes along and dries them off again. They are by no means waterproof.


Regards, NT