Just taken the T&G ceiling down in the kitchen (made of Cedar and stained
mid/dark brown - don't ask like it when I moved in) and now know why it
is so @#%$ing cold in the winter and hot in the summer - no insulation at
all.

The roof is a flat one with a slight slope to the gutter side
(obviously) and room for about 170mm of rockwool. I'll put a vapour
barrier up on the warm side.

The question is - do I need to ventilate the area above the insulation or
can I foam the gaps around the edge of the walls where they meet the
fascia boards (well actually the blocks between the rafters on the inner
leaf of the wall)?

Not a job for now (foam says not to use over 25C), and will take a while
to work out where the lights, power etc. are going when I move the units
around, and the wiring is pants - choc-blox every where etc. and how to
hang some wall units over a work top/island where there is no wall to
hang them on!

Many thanks for any answers.

The Nomad wrote:
Just taken the T&G ceiling down in the kitchen (made of Cedar and stained
mid/dark brown - don't ask like it when I moved in) and now know why it
is so @#%$ing cold in the winter and hot in the summer - no insulation at
all.

The roof is a flat one with a slight slope to the gutter side
(obviously) and room for about 170mm of rockwool. I'll put a vapour
barrier up on the warm side.

The question is - do I need to ventilate the area above the insulation or
can I foam the gaps around the edge of the walls where they meet the
fascia boards (well actually the blocks between the rafters on the inner
leaf of the wall)?

If the space is vented, already at the soffts etc, then you should leave
gaps. Otherwise seal up tight.


Not a job for now (foam says not to use over 25C), and will take a while
to work out where the lights, power etc. are going when I move the units
around, and the wiring is pants - choc-blox every where etc. and how to
hang some wall units over a work top/island where there is no wall to
hang them on!

back to back on chrome poles. :-)

That's what most people do.



Many thanks for any answers.

On Sun, 04 Jul 2010 18:58:37 +0100, The Natural Philosopher wrote:

The Nomad wrote:
Just taken the T&G ceiling down in the kitchen (made of Cedar and
stained mid/dark brown - don't ask like it when I moved in) and now
know why it is so @#%$ing cold in the winter and hot in the summer - no
insulation at all.

The roof is a flat one with a slight slope to the gutter side
(obviously) and room for about 170mm of rockwool. I'll put a vapour
barrier up on the warm side.

The question is - do I need to ventilate the area above the insulation
or can I foam the gaps around the edge of the walls where they meet the
fascia boards (well actually the blocks between the rafters on the
inner leaf of the wall)?

If the space is vented, already at the soffts etc, then you should leave
gaps. Otherwise seal up tight.

Not as such - just very poorly fitting fascias direct onto wall - no
soffit so looks like out with the squirty stuff then.

Not a job for now (foam says not to use over 25C), and will take a
while to work out where the lights, power etc. are going when I move
the units around, and the wiring is pants - choc-blox every where etc.
and how to hang some wall units over a work top/island where there is
no wall to hang them on!

back to back on chrome poles. :-)

That's what most people do.

Puts one in mind of 70's discos etc. I have been thinking how to hang
from the bases (IYSWIM) as I know where the strong bits of the ceiling
are (for now). Or to stand them on poles (not Poles).


Many thanks for any answers.

The Nomad
wibbled on Sunday 04 July 2010 18:43

Just taken the T&G ceiling down in the kitchen (made of Cedar and stained
mid/dark brown - don't ask like it when I moved in) and now know why it
is so @#%$ing cold in the winter and hot in the summer - no insulation at
all.

The roof is a flat one with a slight slope to the gutter side
(obviously) and room for about 170mm of rockwool. I'll put a vapour
barrier up on the warm side.

The question is - do I need to ventilate the area above the insulation or
can I foam the gaps around the edge of the walls where they meet the
fascia boards (well actually the blocks between the rafters on the inner
leaf of the wall)?

Not a job for now (foam says not to use over 25C), and will take a while
to work out where the lights, power etc. are going when I move the units
around, and the wiring is pants - choc-blox every where etc. and how to
hang some wall units over a work top/island where there is no wall to
hang them on!

Many thanks for any answers.

Tricky to be definitive. It's a kitchen so there's higher than normal
humidity and no matter how well you PB the ceiling with vapour barrier PB
(which is recommended if you use plasterboard) some will get through.

So ventilation is prudent - but how much depends. Does any of the rest of
the roof depend on air from here to ventilate it?

If not, you could probably get away with leaving an inch above the wool or
none if it's not too long a length and relying on leakage at the fascia
which in this case I would not seal up tight under any circumstances as
that's inviting trouble.

I did a similar exercise with some bay windows that were causing
condensation on the ceiling below, using 2" celotex and 2" air gap above
with actual round vents added to the soffits. In this case, the bays need to
provide a through path for air to ventilate the rest of the roof structure
hence the full 2" gap as recommended by the building regs. I didn't have any
vapour barrier PB to hand (read, I ordered the wrong stuff!) so I evo-stik'd
some ali foil on to make my own.

The ceilings are considerably warmer with only 2" (about 4" equivalent of
rockwool) so your 7" should make a huge difference.

I wouldn't be too pedantic about the 25C re foam unless you're working in
direct sunlight on sun baked structures. I foamed the bay insulation in
place in temperatures similar to now and it was fine.

HTH

Tim

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

On Jul 4, 9:20*pm, Tim Watts wrote:
The ceilings are considerably warmer with only 2" (about 4" equivalent of
rockwool) so your 7" should make a huge difference.

Can I suggest a slightly different approach. Put the Rockwool in. Are
you holding it up with netting?? It might be easier, though more
costly to wedge in 100mm celotex type insulation. Then board the
entire underside with 25mm celotex. Foil tape the joins. Then fix
regular plasterboard to that. I took a similar approach to a bedroom
ceiling and the result has very effective, both in winter and summer.



Dave.

On 4 July, 18:43, The Nomad wrote:
Just taken the T&G ceiling down in the kitchen (made of Cedar and stained
mid/dark brown - don't ask like it when I moved in) and now know why it
is so @#%$ing cold in the winter and hot in the summer - no insulation at
all.

The roof is *a flat one with a slight slope to the gutter side
(obviously) and room for about 170mm of rockwool. *I'll put a vapour
barrier up on the warm side.

The question is - do I need to ventilate the area above the insulation or
can I foam the gaps around the edge of the walls where they meet the
fascia boards (well actually the blocks between the rafters on the inner
leaf of the wall)?

Not a job for now (foam says not to use over 25C), and will take a while
to work out where the lights, power etc. are going when I move the units
around, and the wiring is pants - choc-blox every where etc. and how to
hang some wall units over a work top/island where there is no wall to
hang them on!

Many thanks for any answers.

You need ventilation between insulation a roof. This is to prevent
condensation. Also keeps it a bit cooler for the electric wiring. Yes.
your vapour barrier is essential. Be sure to mesh ventilation holes to
keep out birds and mice etc.
Or ridgid foam insulation might be the way to go. Cut 1" narrower
than joist space and fill 1/2"gaps with canned foam. You will need to
support temporarily with some nails into joists. Finish will plaster
board with the stuck on foil.
It is actually a lot easier to do PB first & put the insulation on top
but maybe not enough space above in your case.

On Sun, 04 Jul 2010 14:15:58 -0700, harry wrote:

On 4 July, 18:43, The Nomad wrote:
Just taken the T&G ceiling down in the kitchen (made of Cedar and
stained mid/dark brown - don't ask like it when I moved in) and now
know why it is so @#%$ing cold in the winter and hot in the summer - no
insulation at all.

The roof is Â*a flat one with a slight slope to the gutter side
(obviously) and room for about 170mm of rockwool. Â*I'll put a vapour
barrier up on the warm side.

The question is - do I need to ventilate the area above the insulation
or can I foam the gaps around the edge of the walls where they meet the
fascia boards (well actually the blocks between the rafters on the
inner leaf of the wall)?

Not a job for now (foam says not to use over 25C), and will take a
while to work out where the lights, power etc. are going when I move
the units around, and the wiring is pants - choc-blox every where etc.
and how to hang some wall units over a work top/island where there is
no wall to hang them on!

Many thanks for any answers.

You need ventilation between insulation a roof. This is to prevent
condensation. Also keeps it a bit cooler for the electric wiring. Yes.
your vapour barrier is essential. Be sure to mesh ventilation holes to
keep out birds and mice etc.

No soffits, only gaps are where fascia boards meet the wall (or not) -
wasps have got in in the past - there are old nests there.

Wiring has been drilled through the middle of the beams ;-(

Or ridgid foam insulation might be the way to go. Cut 1" narrower
than joist space and fill 1/2"gaps with canned foam. You will need to
support temporarily with some nails into joists. Finish will plaster
board with the stuck on foil.

Had actually thought about plastic VB rather than foil lined PB

It is actually a lot easier to do PB first & put the insulation on top
but maybe not enough space above in your case.

Worse no access - the roof is a flat one and I am NOT taking that off !