On 22/06/2019 21:48, Tim Lamb wrote:
In message , The Natural Philosopher
writes
On 22/06/2019 20:43, Tim Lamb wrote:
In message , "dennis@home"
writes
On 22/06/2019 09:31, Tim Lamb wrote:
In message , Brian Reay
writes
Jim GM4DHJ ... wrote:
why do the English not use sarking ? ....




They do.

Some older houses may not have it but more modern ones certainly
do.Â* All
the houses we own/have owned have sarking felt.
Â*Huh! Now try and get your builder to use it!
They have latched on to porous membrane in the firm belief that
roofÂ* ventilation is no longer necessary. Also try and get them to
use theÂ* grade required for your area wind prediction and double
sided tapeÂ* for laps:-(


Building regs require roof vents so they will fit them.
Â*None fitted here. Building control were stressy about maintaining a
50mmÂ* gap between the insulation and the membrane but ignored the
lack ofÂ* soffit vents.

Not even ridge vents?

No. Mind, these are Marley rolled concrete tiles so hardly an airtight
fit. They did fit plastic eyelashes to discourage birds and insects at
the eaves.



So is this a 'warm' roof with the insulation up at the tile level?
And they didnt insist on venting it?

Ther is a certain login in that internal moisture simply won't get past
all that foil and tape, compared to e.g. rockwool.
So the need for massive vents to prevent rafter rot is not there






--
If you tell a lie big enough and keep repeating it, people will
eventually come to believe it. The lie can be maintained only for such
time as the State can shield the people from the political, economic
and/or military consequences of the lie. It thus becomes vitally
important for the State to use all of its powers to repress dissent, for
the truth is the mortal enemy of the lie, and thus by extension, the
truth is the greatest enemy of the State.

Joseph Goebbels