An external wall in an extension I'm building is specified as 0.34U value,
made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

As this is a kitchen / diner extension, I'm keen to tile directly on to the
thermalite and leave out the drylining in order to make it easier to fix
kitchen cabinets etc.
What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be interested?
BTW the extension was started prior to April 6 2006.
Regards
Donwill

Donwill wrote:
An external wall in an extension I'm building is specified as 0.34U value,
made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

As this is a kitchen / diner extension, I'm keen to tile directly on to the
thermalite and leave out the drylining in order to make it easier to fix
kitchen cabinets etc.
What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be interested?
BTW the extension was started prior to April 6 2006.

I wouldn't have thought it would make much difference as it is going to
be clad in kitchen units. There will only be a strip of some 18 inches
between the worktop and the wall cupboards. And maybe another 18 above.
(Not sure.)

I'd put the plasterbard strip in the middle to facilitate tiling.

But you can get a firm fix to plasterboard with a strip of baton. Just
mark where the cupboards are going and fix the baton with shell fixings
and no nails. Then screw the cupboards to the baton.

Put one underneath with masonry nails as hooks to hold mugs and stuff.
Actually you can bury a par 2 x 1 batton in the back of each unit as
the sides go past the back by that depth.

Do not, repeat NOT tile directly onto the thermalite. They will almost
certainly suffer drying/shrinkage cracks, which could cause the tile to
crack or fall off.

Dry line & then fix the tiles on the p/board to remove an problems.

I sold Thermalite for 3 years, and I can't remember the number of
shrinkage cracks I saw.....

Many thanks, I'll take your advice, I would hate to see them all falling off
the wall.
Cheers
Donwill

Donwill wrote:
An external wall in an extension I'm building is specified as 0.34U value,
made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

As this is a kitchen / diner extension, I'm keen to tile directly on to the
thermalite and leave out the drylining in order to make it easier to fix
kitchen cabinets etc.

Almost none. The kingpsan alone is about 90% of the insulation.

What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be interested?
BTW the extension was started prior to April 6 2006.

Do the sums yourself.

Regards
Donwill

"The Natural Philosopher" wrote in message
...
Donwill wrote:
An external wall in an extension I'm building is specified as 0.34U
value, made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

As this is a kitchen / diner extension, I'm keen to tile directly on to
the thermalite and leave out the drylining in order to make it easier to
fix kitchen cabinets etc.

Almost none. The kingpsan alone is about 90% of the insulation.

What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be
interested?
BTW the extension was started prior to April 6 2006.

Do the sums yourself.

I believe you add up the resistances as they are in series, trouble is I
dont know what value to give to the individual resistances except for the
Kingspan. I've not seen a figure given for the gap behind drylining, I
assume it varies according to the gap dimension.So maybe you're right the
magnitude of the change in U value will not exite the BI.
Cheers
Donwill

Donwill wrote:
"The Natural Philosopher" wrote in message
...
Donwill wrote:
An external wall in an extension I'm building is specified as 0.34U
value, made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

As this is a kitchen / diner extension, I'm keen to tile directly on to
the thermalite and leave out the drylining in order to make it easier to
fix kitchen cabinets etc.
Almost none. The kingpsan alone is about 90% of the insulation.

What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be
interested?
BTW the extension was started prior to April 6 2006.
Do the sums yourself.

I believe you add up the resistances as they are in series, trouble is I
dont know what value to give to the individual resistances except for the
Kingspan. I've not seen a figure given for the gap behind drylining, I
assume it varies according to the gap dimension.So maybe you're right the
magnitude of the change in U value will not exite the BI.
Cheers
Donwill


No, it won't. I have all the info and data and have dine similar calcs.
However listen to the man who advises not tiling onto block directly -
he seems to have a valid point.

On Fri, 21 Apr 2006 10:55:29 +0100, a particular chimpanzee named
"Donwill" popple @diddle .dot randomly hit the keyboard and
produced:

An external wall in an extension I'm building is specified as 0.34U value,
made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be interested?

The wall construction will certainly give the maximum required U-value
of 0.35W/m²K without the dot-&-dab. I would have thought it would
give a lot less.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"

Hugo Nebula wrote:
On Fri, 21 Apr 2006 10:55:29 +0100, a particular chimpanzee named
"Donwill" popple @diddle .dot randomly hit the keyboard and
produced:

An external wall in an extension I'm building is specified as 0.34U value,
made up as follows:-
Externally rendered 100mm dense concrete blockwork.
80mm cavity part-filled with 40mm Kingspan TW50.
Inner leaf 100mm thermalite block.
Drylined internally with 9.5mm plasterboard and skim.

What will be the thermal effect of leaving out the drylining, and by how
much will the U value be changed.Will the building inspector be interested?

The wall construction will certainly give the maximum required U-value
of 0.35W/m²K without the dot-&-dab. I would have thought it would
give a lot less.
I think you mean minimum.

snipped
I believe you add up the resistances as they are in series, trouble is I
dont know what value to give to the individual resistances except for the
Kingspan. I've not seen a figure given for the gap behind drylining, I
assume it varies according to the gap dimension.So maybe you're right the
magnitude of the change in U value will not exite the BI.
Cheers
Donwill


No, it won't. I have all the info and data and have dine similar calcs.
However listen to the man who advises not tiling onto block directly - he
seems to have a valid point.

Agreed!! as stated in my reply to him earlier.
Regards
Donwill

On Sun, 23 Apr 2006 00:12:57 +0100, a particular chimpanzee named The
Natural Philosopher randomly hit the keyboard and produced:

Hugo Nebula wrote:

The wall construction will certainly give the maximum required U-value
of 0.35W/m²K without the dot-&-dab. I would have thought it would
give a lot less.

I think you mean minimum.

No, maximum. A U-value is a measure of the heat transmitted through
1m² of the construction per degree difference in temperature, and the
lower the better. The requirements for extensions give a _maximum_
permitted U-value of 0.35W/m²K.
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"