Just had the estimator round to get the loft insulation topped up.
Particularly because of the very shallow pitch of the roof I'm concerned
that the 250mm insulation will block the natural ventilation round the
eaves.

What methods are the installers likely to use to get round this, and how
do I check they've done it?

--
Skipweasel
Pay no attention to that man behind the curtain.

Just had the estimator round to get the loft insulation topped up.
Particularly because of the very shallow pitch of the roof I'm concerned
that the 250mm insulation will block the natural ventilation round the
eaves.

What is the roof covering? Is sarking present? What is the sarking made
from?

Christian.

On Fri, 26 May 2006 13:37:18 +0100, Guy King
wrote:

Just had the estimator round to get the loft insulation topped up.
Particularly because of the very shallow pitch of the roof I'm concerned
that the 250mm insulation will block the natural ventilation round the
eaves.
I've just been working in among the rockwool in my shallow pitched
roof. Horrible, itchy experience. I don't know how much ventilation
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? If so, you could make sure there's a
similar effect after they've finished the job. If there's noticeable
air movement on a lightly breezy day, it should indicate a significant
amount of ventilation eh?. I certainly wouldn't want to crawl around
in the stuff any more than necessary if it's rockwool or fibreglass.
Perhaps you've gone for the more literary type material?

What methods are the installers likely to use to get round this, and how
do I check they've done it?

--
Regards,
Mike Halmarack

Drop the (EGG) to email me.

The message
from "Christian McArdle" contains
these words:

What is the roof covering? Is sarking present? What is the sarking made
from?

Late 60s early 70s Marley (type) tile roof with felt sarking.

--
Skipweasel
Pay no attention to that man behind the curtain.

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?

Ah, it's a terrace so there's no way of having a vent in the dividing
wall - unless I want to smell nextdoor's fags even more than I already
do.

--
Skipweasel
Pay no attention to that man behind the curtain.

On Fri, 26 May 2006 22:43:39 +0100, Guy King
wrote:

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?

Ah, it's a terrace so there's no way of having a vent in the dividing
wall - unless I want to smell nextdoor's fags even more than I already
do.
As long as it doesn't have you frantically diving into the bin
looking for old dog-ends. :-)
--
Regards,
Mike Halmarack

Drop the (EGG) to email me.

The message
from Mike Halmarack ... contains these words:

Ah, it's a terrace so there's no way of having a vent in the dividing
wall - unless I want to smell nextdoor's fags even more than I already
do.
As long as it doesn't have you frantically diving into the bin
looking for old dog-ends. :-)

Nah, I gave up nearly eight years ago. The only time I miss it is at the
end of one bit of a job before I start the next. The time when I would
have had a fag and a coffee and a sit down to think what to do next.

--
Skipweasel
Pay no attention to that man behind the curtain.

"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

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 ;-

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...

The message
from "keith_765" contains these words:

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.

Some of the houses round here which have had mucho insulation fitted
have these.

What about eaves trays?

--
Skipweasel
Pay no attention to that man behind the curtain.

"Guy King" wrote in message
...
The message
from "keith_765" contains these words:

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.

Some of the houses round here which have had mucho insulation fitted
have these.

What about eaves trays?
To fit eave trays you have to take off the roof covering. Which type of eave
vent system are you referring to.
1) Full eaves vent system including, over fascia vent strips, with felt vent
support tray.
2) Over fascia vent in one.

http://www.cemex.co.uk/page.asp?id=2789 Try this.

Which ever you use, you will have to take off about 600mm x length of the
building, of roof covering at eaves level.

KS Notts