Tubular heater size?

[JohnD]

Looking at the price per sq.m, it seems you can get 50mm thich polystyrene at £7.99 per m2

And the extra cost of the better PIR will not recoup much extra saving.

If you fix it to the face of the studs, it will easier than cutting to fit between, and will give better results.

Do not allow polystyrene to touch plastic parts, especially electrical cable, which it degrades

 

[Harry Bloomfield]

Looking at the price per sq.m, it seems you can get 50mm thich polystyrene at £7.99 per m2

There are two versions of polystyrene available, the normal variety as used for packaging, and a flame-retardant treated version, which costs around 10% more. I would suggest the latter is worth paying the extra for.

 

[Davecl]

Looking at the price per sq.m, it seems you can get 50mm thich polystyrene at £7.99 per m2

And the extra cost of the better PIR will not recoup much extra saving.

If you fix it to the face of the studs, it will easier than cutting to fit between, and will give better results.

Do not allow polystyrene to touch plastic parts, especially electrical cable, which it degrades

Thank you so much for all your help, you are a star.
Polystyrene it is.. oh and special thanks for the plastic tip

 

[Davecl]

There are two versions of polystyrene available, the normal variety as used for packaging, and a flame-retardant treated version, which costs around 10% more. I would suggest the latter is worth paying the extra for.

Good call, thanks