I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had assumed
that it would be necessary/best to fill the cavity but investigations suggest
that less than 1/3 this thickness seems to be generally used.
Is one option a false economy or the other a waste of money?

NB We are intending to use the room in all seasons.

--
John Cartmell john@ followed by finnybank.com 0845 006 8822
Qercus magazine FAX +44 (0)8700-519-527 www.finnybank.com
Qercus - the best guide to RISC OS computing

On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:

I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had assumed
that it would be necessary/best to fill the cavity but investigations suggest
that less than 1/3 this thickness seems to be generally used.
Is one option a false economy or the other a waste of money?

NB We are intending to use the room in all seasons.



Yes it does make sense to fill it. Insulating foam or insulating
glass fibre or Rockwool batts are typical.

However, if it is a dwarf wall - say up to about 6 courses of bricks -
then the glass will represent the bulk of the heat loss anyway.

It is worth going for low emissivity glass with the double glazing
space gas filled.

Another thing that should be included is to insulate the floor.
Styrofoam is used for this, I believe typically of 100mm thickness,
and is quite cheap.



--

..andy

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In article , Andy Hall
wrote:
On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:

I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had
assumed that it would be necessary/best to fill the cavity but
investigations suggest that less than 1/3 this thickness seems to be
generally used. Is one option a false economy or the other a waste of
money?

NB We are intending to use the room in all seasons.



Yes it does make sense to fill it. Insulating foam or insulating glass
fibre or Rockwool batts are typical.

Thanks.
It made sense to me but every (commercially built) one that I checked seemed
to have used something like 1-2cm thick foam. Cheap?

--
John Cartmell john@ followed by finnybank.com 0845 006 8822
Qercus magazine FAX +44 (0)8700-519-527 www.finnybank.com
Qercus - the best guide to RISC OS computing

On Fri, 22 Jul 2005 22:46:28 +0100, John Cartmell
wrote:

In article , Andy Hall
wrote:
On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:

I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had
assumed that it would be necessary/best to fill the cavity but
investigations suggest that less than 1/3 this thickness seems to be
generally used. Is one option a false economy or the other a waste of
money?

NB We are intending to use the room in all seasons.



Yes it does make sense to fill it. Insulating foam or insulating glass
fibre or Rockwool batts are typical.

Thanks.
It made sense to me but every (commercially built) one that I checked seemed
to have used something like 1-2cm thick foam. Cheap?


Probably.



--

..andy

To email, substitute .nospam with .gl

On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:

I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had assumed
that it would be necessary/best to fill the cavity but investigations suggest
that less than 1/3 this thickness seems to be generally used.
Is one option a false economy or the other a waste of money?

NB We are intending to use the room in all seasons.

From whant I found when I built my house, u have 2 choices

100mm full-fill cavity bats, they must be the "full fill" type.

OR

50mm kingspan, held against inner leaf.

Both have the same U value. The kangspan can not be used as "full
fill".

The floor, you can put 100mm kingspan in.

Having said this, the windows are gonna be a much bigger heat
loss/gain problem.


Rick

John Cartmell wrote:

In article , Rick
wrote:

On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:


I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had
assumed that it would be necessary/best to fill the cavity but
investigations suggest that less than 1/3 this thickness seems to be
generally used. Is one option a false economy or the other a waste of
money?

NB We are intending to use the room in all seasons.


From whant I found when I built my house, u have 2 choices


100mm full-fill cavity bats, they must be the "full fill" type.


OR


50mm kingspan, held against inner leaf.


Both have the same U value. The kangspan can not be used as "full fill".


The floor, you can put 100mm kingspan in.


Many thanks for those leads.


Having said this, the windows are gonna be a much bigger heat loss/gain
problem.


Very true! ;-)


Well. yes and no. Per unit area, yes, if left with curtains undrawn.

BUT.

(i) Windows are a small fraction of the total wall area
(ii) heat gain through them even in winter sun is considerable
(iii) if draightproof and tioghtly closed, use of thick interlined and
lined curtains turns them into a perfect insulation sandwich.

I've got single glazed windows but well curtained and sealed, and
believe me, they keep the cold out. Condensation is the most problematic
in the rooms without open fires

"Rick" wrote in message
...
On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:

I'm looking to add insulation to the cavity in a conservatory wall during
building but I'm not clear what thickness of material to use. I had
assumed
that it would be necessary/best to fill the cavity but investigations
suggest
that less than 1/3 this thickness seems to be generally used.
Is one option a false economy or the other a waste of money?

NB We are intending to use the room in all seasons.

From whant I found when I built my house, u have 2 choices

100mm full-fill cavity bats, they must be the "full fill" type.

OR

50mm kingspan, held against inner leaf.

Both have the same U value. The kangspan can not be used as "full
fill".

The floor, you can put 100mm kingspan in.

Having said this, the windows are gonna be a much bigger heat
loss/gain problem.

It all adds up. The floor is a large area and added to the dwarf walls a
reasonable percentage of the overall area, so worth insulation well. If the
conservatory is against the outside wall of the house the conservatory acts
as an extra layer of insulation on that wall. As no rain will penetrate
this section outside wall, full filling the house wall against the
conservatory is a good thing. The problem is getting inside the cavity, so
a spray in foam would need to be used.

The Natural Philosopher wrote:
John Cartmell wrote:

In article , Rick
wrote:

On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:


I'm looking to add insulation to the cavity in a conservatory wall
snip

Having said this, the windows are gonna be a much bigger heat
loss/gain problem.


Very true! ;-)


Well. yes and no. Per unit area, yes, if left with curtains undrawn.

BUT.

(i) Windows are a small fraction of the total wall area

Umm.. It's a conservatory...

(ii) heat gain through them even in winter sun is considerable
(iii) if draightproof and tioghtly closed, use of thick interlined and
lined curtains turns them into a perfect insulation sandwich.

I've got single glazed windows but well curtained and sealed, and
believe me, they keep the cold out. Condensation is the most
problematic in the rooms without open fires

A single glazed conservatory would be cold, whatever. Evene if you also had
insulated roof blinds...

On Sat, 23 Jul 2005 10:18:19 +0100, The Natural Philosopher
wrote:



Well. yes and no. Per unit area, yes, if left with curtains undrawn.

BUT.

(i) Windows are a small fraction of the total wall area
(ii) heat gain through them even in winter sun is considerable
(iii) if draightproof and tioghtly closed, use of thick interlined and
lined curtains turns them into a perfect insulation sandwich.

I've got single glazed windows but well curtained and sealed, and
believe me, they keep the cold out. Condensation is the most problematic
in the rooms without open fires

All true apart from a)... it's a conservatory......

--

..andy

To email, substitute .nospam with .gl

"PC Paul" wrote in message
k...
The Natural Philosopher wrote:
John Cartmell wrote:

In article , Rick
wrote:

On Fri, 22 Jul 2005 21:09:32 +0100, John Cartmell
wrote:


I'm looking to add insulation to the cavity in a conservatory wall
snip

Having said this, the windows are gonna be a much bigger heat
loss/gain problem.


Very true! ;-)


Well. yes and no. Per unit area, yes, if left with curtains undrawn.

BUT.

(i) Windows are a small fraction of the total wall area

Umm.. It's a conservatory...

He has been at the sherry again.

On Sat, 23 Jul 2005 10:38:21 +0100, "Doctor Drivel"
wrote:


It all adds up. The floor is a large area and added to the dwarf walls a
reasonable percentage of the overall area, so worth insulation well. If the
conservatory is against the outside wall of the house the conservatory acts
as an extra layer of insulation on that wall. As no rain will penetrate
this section outside wall, full filling the house wall against the
conservatory is a good thing.

The problem is getting inside the cavity, so
a spray in foam would need to be used.

??? You can insert insulating batts or Celotex while the wall is being
built.




--

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Sat, 23 Jul 2005 10:38:21 +0100, "Doctor Drivel"
wrote:


It all adds up. The floor is a large area and added to the dwarf walls a
reasonable percentage of the overall area, so worth insulation well. If
the
conservatory is against the outside wall of the house the conservatory
acts
as an extra layer of insulation on that wall. As no rain will penetrate
this section outside wall, full filling the house wall against the
conservatory is a good thing.

The problem is getting inside the cavity, so
a spray in foam would need to be used.

??? You can insert insulating batts or Celotex while the wall is being
built.

The existing house wall. Duh!

On Sat, 23 Jul 2005 11:31:07 +0100, "Doctor Drivel"
wrote:


"Andy Hall" wrote in message
.. .
On Sat, 23 Jul 2005 10:38:21 +0100, "Doctor Drivel"
wrote:


It all adds up. The floor is a large area and added to the dwarf walls a
reasonable percentage of the overall area, so worth insulation well. If
the
conservatory is against the outside wall of the house the conservatory
acts
as an extra layer of insulation on that wall. As no rain will penetrate
this section outside wall, full filling the house wall against the
conservatory is a good thing.

The problem is getting inside the cavity, so
a spray in foam would need to be used.

??? You can insert insulating batts or Celotex while the wall is being
built.

The existing house wall. Duh!

The question was about the new wall not the existing. Try to keep
up.



--

..andy

To email, substitute .nospam with .gl

"Andy Hall" wrote in message
...
On Sat, 23 Jul 2005 11:31:07 +0100, "Doctor Drivel"
wrote:


"Andy Hall" wrote in message
.. .
On Sat, 23 Jul 2005 10:38:21 +0100, "Doctor Drivel"
wrote:


It all adds up. The floor is a large area and added to the dwarf
walls a
reasonable percentage of the overall area, so worth insulation well.
If
the
conservatory is against the outside wall of the house the conservatory
acts
as an extra layer of insulation on that wall. As no rain will
penetrate
this section outside wall, full filling the house wall against the
conservatory is a good thing.

The problem is getting inside the cavity, so
a spray in foam would need to be used.

??? You can insert insulating batts or Celotex while the wall is being
built.

The existing house wall. Duh!

The question was about the new wall not the existing. Try to keep
up.

You must learn to focus.