Tim S wrote:

keith_765 wrote:


"Guy King" wrote in message
...
The message
from Mike Halmarack ... contains these words:

occurs naturally up there via the eaves but I do know that with an
airbrick in each opposing gable wall, there's a pretty constant and
very noticeable breeze. Do you notice much air movement if you stick
your head above the parapet?

Ask the insulation contractor not to push the insulation up to the back
of
the felt underlay, leave a 25mm gap from the felt. If the insulation is
pushed up to the felt underlay, the alternative is to fit vent tiles
above the height of the insulation every 1.6 metres both eaves to cause
an air
cross flow. There are GRP vent tiles to fit all concrete Marley,
Sandtoft, Redland and Russell tiles, both plain and interlocking. Just
take out the tile cut the underlay, fold back or inwards and replace the
tile with a vent tile.

K,S Notts

For what it's worth, 50mm (2") gap is the norm in England [1] (and
reckoned to be a fairly safe bet, combined with sufficient ventilation top
and bottom) - probably to allow a bit in case the sarking sags.

Cheers

Tim

[1] obvious building regulations/codes are different, but rot doesn't
respect borders ;-

Ignore the "UK" bit - for some reason I thought I was posting to an
international group :~ Need beer...

50mm is still recommended though...