Cooling tips

[noseall]

Seen some sense, at last perhaps!

The sun is immense, no doubt.
It will warm the bricks and may warm the outer surface of the PIR foil if it passes through the first air gap. It won't warm the blockwork on the other side of the PIR and not alter the surface temperature of the wall inside one jot. - no.

Eventually or inevitably on a day to day cycle in the UK - no.

 

[Highway Man]

I always thought heat loss was through your walls and why you had cavity wall insulation so it goes that heat would also travel through from the outside in?

 

[gas112]

I always thought heat loss was through your walls and why you had cavity wall insulation so it goes that heat would also travel through from the outside in?

it does
if you use nosealls logic there would be no heat loss from a building in winter which we know doesnt happen

 

[motorbiking]

And no need to make walls 350mm thick when 50mm of PIR will stop all heat loss. His hand test has proved it.

 

[noseall]

And no need to make walls 350mm thick

Belt & braces.
We're all wondering when they'll makes us build them 400mm.
I fitted a 350mm wide window board yesterday. You could probably play table tennis on it.
Most of our builds since the rule change have been 100mm cavity with interlocking PIR.

 

[noseall]

I always thought heat loss was through your walls

Most of it is through the openings and air leakage.
The walls are the most efficient part of the protective envelope.

 

[gas112]

Most of it is through the openings and air leakage.
The walls are the most efficient part of the protective envelope.

Most is not all .
there is also conducted and radiated heat loss

 

[Harry Bloomfield]

I always thought heat loss was through your walls and why you had cavity wall insulation so it goes that heat would also travel through from the outside in?

No it doesn't, cannot prevent heat loss, or gain. All it does. can do, is slow the transfer down. No matter how thick/good the insulation is, heat or cold will eventually find it's way through, unless you live in nosealls parallel universe.

 

[Harry Bloomfield]

Most of it is through the openings and air leakage.
The walls are the most efficient part of the protective envelope.

A correct statement at last, well done!

 

[MNW67]

I always thought heat loss was through your walls and why you had cavity wall insulation so it goes that heat would also travel through from the outside in?

That is true.

In the summer you have got two competing factors. The insulation in the walls slows down the transfer of heat from outside, keeping the house cooler. But it also slows down the loss of heat from inside the house, keeping the house warmer.

 

[motorbiking]

Belt & braces.
We're all wondering when they'll makes us build them 400mm.
I fitted a 350mm wide window board yesterday. You could probably play table tennis on it.
Most of our builds since the rule change have been 100mm cavity with interlocking PIR.

and if you knew how to calculate U values, your current project could have been delivered with a saving of space and money, to the client, with a minor tweak to the specification.

110mm celotex replacing 50mm air + 100mm celotex.

It won't for example pass through 103mm of brick, 50mm air gap, 100mm of Celotex, 100mm block and 25mm of dabbed plasterboard so long as you've got a hole up your arse.

 

[noseall]

and if you knew how to calculate U values, your current project could have been delivered with a saving of space and money, to the client, with a minor tweak to the specification.

110mm celotex replacing 50mm air + 100mm celotex.

We have to use a certain product with full fill PIR. It's actually 90mm (10mm fitting gap) with rebated edges and coated against the wet side etc.
An absolute b'stard to fit up a gable with stepped cav trays etc.

 

[motorbiking]

Some builders fit one row of boards and lift it up with each row of bricks as they go

 

[MNW67]

We have to use a certain product with full fill PIR. It's actually 90mm (10mm fitting gap) with rebated edges and coated against the wet side etc.

Is the gap so that you can fit the retaining disc?

 

[noseall]

Is the gap so that you can fit the retaining disc?

View attachment 385381

It's more for discrepancy in the masonry. You would not be able to fit it if you tried to make the cavs 90mm.