Hi all,

as part of the central heating upgrade, I've got the floorboards up.

I am putting in 14 rads, 7 downstairs on its own zone valve, and 7
upstairs, also on its zone valve.

The idea is that while we are sleeping upstairs, theres no point heating
the downstairs, and equally when we are downstairs during the day,
theres no point heating the upstairs.

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction and also should hopefully make
the upstairs rooms more bearable in the summer.

Now is this OK to do, and should I go for 4 or 8 inches?

Needless to say there will be 12 inches in the loft.

Regards

Stephen.

Stephen H wrote:
Hi all,

as part of the central heating upgrade, I've got the floorboards up.

I am putting in 14 rads, 7 downstairs on its own zone valve, and 7
upstairs, also on its zone valve.

The idea is that while we are sleeping upstairs, theres no point heating
the downstairs, and equally when we are downstairs during the day,
theres no point heating the upstairs.

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction and also should hopefully make
the upstairs rooms more bearable in the summer.

Now is this OK to do, and should I go for 4 or 8 inches?

Needless to say there will be 12 inches in the loft.

Regards

Stephen.
Gut feeling is that it would be a waste of effort unless you are going
to religiously close all doors in the house to prevent the insulation
being bypassed by moving air going up stairs.

Bob

"Stephen H" wrote in message
o.uk...
Hi all,

as part of the central heating upgrade, I've got the floorboards up.

I am putting in 14 rads, 7 downstairs on its own zone valve, and 7
upstairs, also on its zone valve.

The idea is that while we are sleeping upstairs, theres no point heating
the downstairs, and equally when we are downstairs during the day, theres
no point heating the upstairs.

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all the
insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction and also should hopefully make the
upstairs rooms more bearable in the summer.

Now is this OK to do, and should I go for 4 or 8 inches?

Needless to say there will be 12 inches in the loft.

Put in Rockwool not glass fibre. this adds sound insulation -well worth it.
Thermal insulation will be minimal. Uprate the insulation in the loft.

On Dec 31, 11:44 am, Stephen H wrote:

snip

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction

and also should hopefully make
the upstairs rooms more bearable in the summer.

er... how?

Jim K

On 31/12/2011 12:07, Jim K wrote:
On Dec 31, 11:44 am, Stephen wrote:

snip

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction

and also should hopefully make
the upstairs rooms more bearable in the summer.

er... how?

Jim K


We have found that in our current house, when we have a hot summer, the
downstairs rooms are cooler than the upstairs rooms.

We assume this is due to warmer air rising and cooler air sinking
through the whole house. So thus if we put in insulation between ground
floor and the 1st floor and keep the room doors shut, it would reduce
the warm air rising from downstairs to upstairs, and reduce the cooler
air sinking from upstairs to downstairs.....

Stephen.

In article ,
Stephen H writes:
Hi all,

as part of the central heating upgrade, I've got the floorboards up.

I am putting in 14 rads, 7 downstairs on its own zone valve, and 7
upstairs, also on its zone valve.

The idea is that while we are sleeping upstairs, theres no point heating
the downstairs, and equally when we are downstairs during the day,
theres no point heating the upstairs.

You won't build up enough temperature differential during those
periods for it to matter. If you intended to only heat one or the
other for many days on end whilst allowing the other one to get
stone cold, then it might be more significant.

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction

You allow for this when doing your heatloss calculations for
sizing the radiators.

and also should hopefully make
the upstairs rooms more bearable in the summer.

How?

Now is this OK to do, and should I go for 4 or 8 inches?

None at all.

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

You allow for this when doing your heatloss calculations for
sizing the radiators.


Talking of Heat loss calculations, I did this for fabric heatloss and
ventilation heatloss.

I found a source of U values on a website somewhere and they are as follows

Surface material W/m2°C
plasterboard ceiling with 4in fibreglass, felted & tiled roof 0.3
suspended wood floor 1.7
double skin wall & air cavity 1
Stud & partition 1.8
DG UPVC 1.7
Wood 1.8

I notice that the the U value for a double skin wall with air cavity has
a U value of 1.0. Now for a plasterboard ceiling with 4 inches
fibreglass has a U value of 0.3 That is suggesting that plasterboard and
4 inches of fibreglass is a better insulator than 4 inch brick, 2 inch
air cavity and 4 inch breeze block....

Is that really the case?

If so the mind boggles as to what the U value would be if that 4inches
of loft insulation was replaced with 12 inches.......

Stephen.

Stephen H wrote:
You allow for this when doing your heatloss calculations for
sizing the radiators.


Talking of Heat loss calculations, I did this for fabric heatloss and
ventilation heatloss.

I found a source of U values on a website somewhere and they are as follows

Surface material W/m2°C
plasterboard ceiling with 4in fibreglass, felted & tiled roof 0.3
suspended wood floor 1.7
double skin wall & air cavity 1
Stud & partition 1.8
DG UPVC 1.7
Wood 1.8

I notice that the the U value for a double skin wall with air cavity has
a U value of 1.0. Now for a plasterboard ceiling with 4 inches
fibreglass has a U value of 0.3 That is suggesting that plasterboard and
4 inches of fibreglass is a better insulator than 4 inch brick, 2 inch
air cavity and 4 inch breeze block....

Is that really the case?


Yes

If so the mind boggles as to what the U value would be if that 4inches
of loft insulation was replaced with 12 inches.......

Irrelevant.

At some level the dominant heat loss becomes ventilation, and also doors
and windows.

Once you are up to 4" of celotex or about 6-8" of rockwool, you are in
the position of needing to go triple argon bull**** ********, and have
double doored porches to the outside world..and heat recovery ventilation.

And probably some form of powered humidity control

Diminishing returns.

The figures suggest that the average poorly built house of 30-300 years
ago will be 3-10 times worse than double glazed cavity insulated
modern.. but ou could treble the cost of the house of today and still
not much more than halve the heatloss.

Better to spend the money on nuclear power stations..;-)




Stephen.

JohnPOn Dec 31, 11:52*am, Bob Minchin
wrote:
Stephen H wrote:
Hi all,

as part of the central heating upgrade, I've got the floorboards up.

I am putting in 14 rads, 7 downstairs on its own zone valve, and 7
upstairs, also on its zone valve.

The idea is that while we are sleeping upstairs, theres no point heating
the downstairs, and equally when we are downstairs during the day,
theres no point heating the upstairs.

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction and also should hopefully make
the upstairs rooms more bearable in the summer.

Now is this OK to do, and should I go for 4 or 8 inches?

Needless to say there will be 12 inches in the loft.

Regards

Stephen.

Gut feeling is that it would be a waste of effort unless you are going
to religiously close all doors in the house to prevent the insulation
being bypassed by moving air going up stairs.

Bob

Plus, if the bathroom/toilets are always heated, for comfort, the
doors must be always closed.

rusty

On 31/12/2011 12:20, Stephen H wrote:

We have found that in our current house, when we have a hot summer, the
downstairs rooms are cooler than the upstairs rooms.

We assume this is due to warmer air rising and cooler air sinking
through the whole house. So thus if we put in insulation between ground
floor and the 1st floor and keep the room doors shut, it would reduce
the warm air rising from downstairs to upstairs, and reduce the cooler
air sinking from upstairs to downstairs.....

Having an unside down house, When I put UFH in the upstairs living areas
I also added rockwool under the 50mm celotex that the UFH was attached
to (between joists) but more for reducing sound coming down into the
bedrooms.
Last spring I also put insulation in the loft taking it from 0mm to
250mm thinking it might reduce the scorching summer temperatures
upstairs.... it didn't stop the upstairs rooms going to 30 degrees or so
last summer but it has reduced heating requirements by a vast amount.

To date I still haven't connected up downstaris bedroom radiators as
bedrooms never drop below 10 degrees even in last years -15
temperatures. Whether this is helped by all the inter-joist insulation I
don't know but having a water bed which is always set at a comfortable
temperature also helps the night-time comfort.

All in all I would think other than for reducing some of the sounds from
a teenagers bedroom/TV etc from coming downstairs there wouldn't be any
benefit in insulating between joists. Best soulution... put the bedrooms
downstairs and the living area upstairs.
;¬)

One other note: if you DO decide to insulate then I would suggest
stringing a bit of wire diagonally back/forth to provide a support to
keep rockwool away from downstairs plasterboard. If you ever have to
reboard a downstairs ceiling (burst pipe re-resign etc) the last thing
you want is to be ripping out damaged ceiling and then be faced with a
mass of rockwool decending on your head/carpets etc.

Pete

On Dec 31 2011, 11:44*am, Stephen H
wrote:
Hi all,

as part of the central heating upgrade, I've got the floorboards up.

I am putting in 14 rads, 7 downstairs on its own zone valve, and 7
upstairs, also on its zone valve.

The idea is that while we are sleeping upstairs, theres no point heating
the downstairs, and equally when we are downstairs during the day,
theres no point heating the upstairs.

Now I am thinking about putting in insulation between the ground floor
ceiling and the first floor floorboards. I know about making sure all
the insulation goes under all power and lighting cables.

The idea is that the heat from downstairs does not inadvertently heat
upstairs through convection/conduction and also should hopefully make
the upstairs rooms more bearable in the summer.

Now is this OK to do, and should I go for 4 or 8 inches?

Needless to say there will be 12 inches in the loft.

Regards

Stephen.

The temp difference that occurs over one day is trivial. Insulating
the 2 zones only results in more uneven central heating. It also will
worsen overheating of upstairs in summer, since heat is no longer
being conducted down. Forget it. Do something useful with the
insulation instead.

Pouring in a load of runny plaster can help with noise transmission by
making the ceiling PB a lot more rigid, and increasing mass some. Once
set, adding a very thin sprinkling of loose sand can help things
further.


NT