Help needed - anyone tried Stylite EPS 70 Insulation?

[Ctxrob20]

Hi, I'm new to this forum so apologies if this has already been discussed (i couldn't find it in 'search' so here goes) and my ramblings.

I'm completely gutting a bungalow and turning it into a dormer bungalow (with completely new roof) and extending out to the side by 4x8m so I'll need a lot of (amongst other things) insulation over the next few months.

The build is up to DPC level and I now need to do the floor pad but Kingspan is expensive and i wondered if there's a cheaper 'non brand' alternative.

To kick off i need 100mm Kingspan for below the concrete in the pad (think it's Thermafloor...). Cheapest i can get it is about £30 + vat from Seconds & Co. However I've seen Stylite EPS 70 here: http://www.insulationexpress.co.uk/...e-EPS-70-Polystyrene-Insulation-Board-SDN.htm which seems a bit cheaper.

Am i getting this completely wrong or is this worth a punt? Does it have the same thermal and rigid properties (if it does, I'll use it for the 'between joist' underfloor heating I'm thinking of putting in at the other side of the house).

Any advice or past experience would be greatly appreciated.

Cheers, Rob

 

[ban-all-sheds]

AFAIK EPS does not perform as well as PIR/PUR, but that doesn't mean it's not good enough.

 

[tony1851]

As above; inch-for-inch thickness it is a little more than 'half as good'.
So a 100 mm kingspan board would have the same insulation value as approx. 180-190mmmm of EPS.

 

[ban-all-sheds]

Ah - but how do they compare after 5,10,20 years installed?