Rockwool Vs. Celotex / Kingspan after 5 years

[davejuk]

I have read that after about 5 years, all or most of the gas in Kingspan will have escaped. At this point, does it offer the same level of insulation as rockwool at the same thickness?

5 years sounds like a very short lifespan for part of the structure of a house to lose its effectiveness.

 

[freddiemercurystwin]

I think the jury is still out on this, there has certainly been cause for concern for this historically though the manufacturers will tell you they have addressed it now with improved manufacturing techniques/materials (well they would wouldn't they).

 

[davejuk]

That's interesting, I didn't realise it wasn't proven. I notice it has gone up in price about 10% since November so maybe they have changed something in the manufacturing process?

With regard to my original question, is the claim from the 'it becomes less effective over time' camp that it will be reduced to the equivelant of the same thickness of rockwool? Or better/worse?

 

[freddiemercurystwin]

With regards to what its eventual thermal conductivity becomes yes I concur, roughly equivalent to Rockwool or polystyrene.

This has been discussed in a couple of threads on here though not for a while. I admit I have been a sceptic in the past though it is difficult to establish any hard and fast facts. Seems to be an industry secret!

 

[tony1851]

Freddie, that's roughly one-half its original insulation value, give or take a bit. Do you think it could go as bad as that? Just wondering.