Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

But then I wuuld lose 4inches of kitchen.

any better ideas?

(As its only 2 square yards price doesnt matter.)


[g]

My Rayburn installer cautioned me about insulation in close contact
with the back - reckons it can get significantly hot at times.

I've had mine stood out well from the wall, so that there is a
substantial bit of studwork faced with cement board and the kingspan
some distance back.

If I didn't have the space to do this, I'd probably use rockwool
rather than kingspan.

RubberBiker wrote:
My Rayburn installer cautioned me about insulation in close contact
with the back - reckons it can get significantly hot at times.

I've had mine stood out well from the wall, so that there is a
substantial bit of studwork faced with cement board and the kingspan
some distance back.

If I didn't have the space to do this, I'd probably use rockwool
rather than kingspan.

Actually a couple of layers of Masterboard are probably better than nothing.

In article ,
"george (dicegeorge)" writes:
Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

I wouldn't put polyisocyanurate close to a fire-based heat source.
Although most polyisocyanurate board has fire retardants added, it
still burns and gives off extremely nasty toxins when exposed to
flames, even when it has enough fire retardant to prevent it self-
sustaining a flame.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel wrote:
In article ,
"george (dicegeorge)" writes:
Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

I wouldn't put polyisocyanurate close to a fire-based heat source.
Although most polyisocyanurate board has fire retardants added, it
still burns and gives off extremely nasty toxins when exposed to
flames, even when it has enough fire retardant to prevent it self-
sustaining a flame.

Indeed. We tried to burn scarp on a fire when building this house. Nasty
clouds of black smoke., never caught fire, but I wouldn't want to breath it.

Its a case for asbestos really innit?

I'll get my coat

On Sep 24, 10:43*am, "george (dicegeorge)"
wrote:
Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

But then I wuuld lose 4inches of kitchen.

any better ideas?

(As its only 2 square yards price doesnt matter.)

[g]

Fibreglass or rockwool must be the ones to go for, behind PB


NT

polyisocyanurate? in kingspan?

Sounds more dangerous than asbestos.
[g]


The Natural Philosopher wrote:
Andrew Gabriel wrote:
In article ,
"george (dicegeorge)" writes:
Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

I wouldn't put polyisocyanurate close to a fire-based heat source.
Although most polyisocyanurate board has fire retardants added, it
still burns and gives off extremely nasty toxins when exposed to
flames, even when it has enough fire retardant to prevent it self-
sustaining a flame.

Indeed. We tried to burn scarp on a fire when building this house. Nasty
clouds of black smoke., never caught fire, but I wouldn't want to breath
it.

Its a case for asbestos really innit?

I'll get my coat

polyisocyanurate in kingspan?
Sounds more dangerous than asbestos.
[g]

polyisocyanurate in kingspan?

Yup - kingspan is polyisocyanurate between two layers of foil. Try
putting a match to a little scrap.

Check with the narrowboat & boat people.
They routinely have wood burners and insulation.

The bare metal burners radiate intense heat.
I think they use refractory tiles + firecement grout + fireboard/
masterboard + insulation.
They can not use normal ceramic + plywood + insulation; the plywood
turns to charcoal.

On Sep 24, 2:54*pm, NT wrote:
Fibreglass or rockwool must be the ones to go for, behind PB

Would a facing wall of insulating blocks be sufficient? Fire retardant
paint to cover it.

Dave.

"george (dicegeorge)" wrote in message
...
Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

But then I wuuld lose 4inches of kitchen.

any better ideas?

(As its only 2 square yards price doesnt matter.)


For 2 sq yards I wouldn't bother.

R wrote:
"george (dicegeorge)" wrote in message
...
Behind the kitchen rayburn is a one inch gap
then a double brick wall (no cavity).

I'm swapping it for a newer one,
so now is the time to insulate behind it.

3 inches of kingspan then plasterboard is one idea.

But then I wuuld lose 4inches of kitchen.

any better ideas?

(As its only 2 square yards price doesnt matter.)


For 2 sq yards I wouldn't bother.



But as heatloss is proportional to temperature difference
and the back of the rayburn may get quite hot
there could be quite a bit of heat loss through the walls,
worth doing something I think
(as well as increasing the air gap)
[g]

In article , george (dicegeorge)
writes

But as heatloss is proportional to temperature difference
and the back of the rayburn may get quite hot
there could be quite a bit of heat loss through the walls,
worth doing something I think
(as well as increasing the air gap)
[g]

Out of curiosity I did a few calcs:

Assuming zero degrees outside and a wall surface temp behind the rayburn
of 60degC then you lose 240W for a 2m area on the single brick (9") wall
you described.

Just an inch of celotex on that would drop the loss to 75W (2" gives
45W).

By comparison, if your kitchen wall is 3m high by 4m wide then the 10m
not behind the rayburn loses 400W (zero outside, 20deg inside).

Total current loss 640W vs total loss for 1" behind rayburn 475W so it's
still going to be a pretty lossy wall.

If you stuck 1" of celotex to the whole wall then stuck on some
plasterboard then the loss for the whole would be 200W which sounds a
bit better.

If you do just decide to go for insulating behind the rayburn, I would
hack the plaster off the wall immediately behind (which is probably 1"
thick) then infill with 1" celotex with a sheet of masterboard over the
top with a good overlap for protection.

How does that sound?
--
fred
BBC3, ITV2/3/4, channels going to the DOGs

thanks everybody for advice and for discussion-
the bit behind the rayburn is the hardest to insulate so i'm
concentrating on that,
the rest of the walls and windows could do with some too
(and when i repair the ceiling the major heatloss through the
floorboards will be cut).

However its just occured to me that maybe
I could put kingspan on the outside of the building
because that wall is ugly outside, and is badly rendered
(thereby using the brickwall as a heat store)
[g]

fred wrote:
In article , george (dicegeorge)
writes

But as heatloss is proportional to temperature difference
and the back of the rayburn may get quite hot
there could be quite a bit of heat loss through the walls,
worth doing something I think
(as well as increasing the air gap)
[g]

Out of curiosity I did a few calcs:

Assuming zero degrees outside and a wall surface temp behind the rayburn
of 60degC then you lose 240W for a 2m area on the single brick (9") wall
you described.

Just an inch of celotex on that would drop the loss to 75W (2" gives 45W).

By comparison, if your kitchen wall is 3m high by 4m wide then the 10m
not behind the rayburn loses 400W (zero outside, 20deg inside).

Total current loss 640W vs total loss for 1" behind rayburn 475W so it's
still going to be a pretty lossy wall.

If you stuck 1" of celotex to the whole wall then stuck on some
plasterboard then the loss for the whole would be 200W which sounds a
bit better.

If you do just decide to go for insulating behind the rayburn, I would
hack the plaster off the wall immediately behind (which is probably 1"
thick) then infill with 1" celotex with a sheet of masterboard over the
top with a good overlap for protection.

How does that sound?

On 26 Sep, 13:55, "george (dicegeorge)" wrote:
thanks everybody for advice and for discussion-
the bit behind the rayburn is the hardest to insulate so i'm
concentrating on that,
the rest of the walls and windows could do with some too
(and when i repair the ceiling the major heatloss through the
floorboards will be cut).

However its just occured to me that maybe
I could put kingspan on the outside of the building
because that wall is ugly outside, and is badly rendered
(thereby using the brickwall as a heat store)
[g]


except the wall will act as a heatsink down through the foundations
and up into any more wall above it?

I'd concentrate on the inside.

cheers
JimK
(PS note bottom post)

On Sep 26, 2:20*pm, jim wrote:
except the wall will act as a heatsink down through the foundations
and up into any more wall above it?

I'd concentrate on the inside.
I agree about not bothering to insulate the outside. I still think the
idea of internal insulating block wall is worth looking at.
Alternatively, if space is such an issue why not make a small wall
built with side on bricks. Leave a centimetre air gap so that it
projects about 75mm from the existing wall. Those bricks will will
then become the thermal store. Surely someone can work out the
resulting heat loss.

dave

jim wrote:
On 26 Sep, 13:55, "george (dicegeorge)" wrote:
thanks everybody for advice and for discussion-
the bit behind the rayburn is the hardest to insulate so i'm
concentrating on that,
the rest of the walls and windows could do with some too
(and when i repair the ceiling the major heatloss through the
floorboards will be cut).

However its just occured to me that maybe
I could put kingspan on the outside of the building
because that wall is ugly outside, and is badly rendered
(thereby using the brickwall as a heat store)
[g]


except the wall will act as a heatsink down through the foundations
and up into any more wall above it?

I'd concentrate on the inside.

cheers
JimK
(PS note bottom post)
But if a yard length of wall is 10 feet high and 1 foot wide
then the heatloss through the side will be 10 times that through the
bottom or top,
but halve that because the inside wont be as cold as the outside,
plus the ground is warmer than the outdoors,
plus wind and rain on the wall cool it even more,
thus it is worth insulating outside of the wall
if I am ever to re-render it etc
[g]