Best method of dry lining

[DIYBaz]

I've got 2"x2" studwork up on a wall ready to dryline, but what's the best way forward? I was going to use Rockwall slab insulation and foil backed plasterboard. Or, should I use kingspan? This seems a more expensive option, but would it give significant benefit? Sorry, R values, U values and all that really are a mystery to me!

Thanks

 

[jeds]

It's dead simple:

Kingspan has a thermal conductivity (k) of 0.021W/m²K

Rockwool slab has a thermal conductivity of 0.037W/m²K

Get rid of the zeros and round up and you have rockwool at about 4 and Kingspan at about 2. Therefore Rockwool allows approximately twice as much heat loss as the Kingspan. Or, if you prefer, the Kingspan is twice as good. Or, 50mm of Kingspan is the same as 100mm of Rockwool. But Kingspan is also much more expensive - you get what you pay for.

Personally I would use Celotex which has a k value of 0.023 (virtually the same as Kingspan) but is usually much cheaper.

 

[DIYBaz]

Cheers John, I think that answers my question. I'm sure I'll regret asking, but how do you work out the actual heat losses, etc. Would like to know if it's financialy worth doing, or if it's going to take 50 years to pay for it's self!

 

[Fluffster]

Google u value calculator. In regards of paying for itself, well energy prices such as gas have doubled in the last couple of years.
However it is more about reducing co levels for the future and keeping whatever heat you produce in your house inside rather than saving your pocket.
A typical example is replacing a system boiler for a condensing one as the installation costs outway any energy savings made.
Pete