Cavity insulation debate - you'll laugh at one of us...!

[Pallatrax]

While ordering our blocks and cavity insulation in the local builders merchant on Saturday morning I get in, what I think is the most ridiculous debate as to what is deemed 'full-fill' cavity wall insulation...

The guy on the counter, who has been selling to the trade for 30 years, was convinced that an insulation product was only 'full-fill' if it had the tongue and groove notch where it joins - and that 100mm fiberglass/rockwool bats were not full-fill!

Is that worrying, or am I misinformed, because my understanding is clear: if the insulation fills the cavity it is 'full-fill - and there is nothing more to it!?

Can you settle this one please?

Cheers
Tom

 

[stuart45]

Full fill just means that the cavity is fully filled, not left with an air gap.
The other type is normally used to save having a backing wall on stone walls.
Both are full fill.

 

[Pallatrax]

Exactly, so the 'toothing' on the bottom of a 450 x 1200 xtratherm board has nowt to do with the term, and as this would probably be a 50mm sheet it should be installed as a partial fill solution!

Thanks - I knew I was right when he wouldn't bet on it!
Tom