Makes sense as so called porous material is only so until muck and growths
block it up.
Brian

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This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Tim Lamb" wrote in message
...
In message , David
writes
Further into the clear out I've found some of those circular white plastic
eaves vents which allow air to circulate up the rafters, over the top and
down the other side. Hole saw as well.

Intended, I think, for boarded over loft ceilings where there is a risk of
condensation next to the roof.

Looking around, nobody seems to have them in this row of houses.

Are they still considered to be a good idea?

Hmm.. builders seem to have latched on to the idea that porous roofing
membrane makes eaves ventilation redundant.

Building Control don't have the same view here! They insisted on a
significant gap between the membrane and any loft insulation.
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Tim Lamb