"Christian McArdle" wrote in message
t...
hmm, I may have completely the wrong term for this - I can't see the
underside of tiles, there's a plastic membrane underneath them (& over
all
the rafters) - the kind that is reinforced with an internal mesh.

Yes. It is this stuff (which would not be original) that prevents you
fully
filling. That's unless you can read the make and it happens to be a
breathable membrane.

There's no requirement for BCO involvement in this is there?

Probably not. I just mean that there might be some difference in opinion
on
whether soffit ventilation is sufficient for an apex roof. It may be
particularly troublesome if there is a rear "extension" with a valley
join,
as is common on Victorian houses, as there will be no through ventilation
on
those sections, particularly on the rear apex section between valley and
ridge.



just had to go up and recheck that! you reminded me that there is an
extension (from where I am typing at this very moment, so can't very well
forget it!) but the construction of the house is such that the apex of this
extension is substantially lower than the main roof apex, which also means
that I am presented by a complete sloping face of the roof on that corner,
with no access into the extension roof.

I'm actually beginning to look forward to doing this job now.

--
Richard Sampson

email me at
richard at olifant d-ot co do-t uk