kingspan, celotex ?

[sweeneyuk]

i need 50mm of insulation to insert between a timber frame, whats the best in terms of performance?

also the foil facing on the celotex, does this prevent the poly insulation reacting with pvc cables as well as being thermally beneficial?

 

[alittlerespect]

If you want some real benefit you should be looking at around 100mm thickness of PIR Insulation material - beyond that the law of diminishing returns kicks-in and you would need to work out the payback time on any additional thickness over 100mm.

With respect to Kingspan or Celotex theres not a lot of difference, although I believe that Celotex has the advantage at this time in terms of performance - but check out the spec's for the materials.

Regards

 

[freddiemercurystwin]

There is no significant difference, purchase whichever you can get the better deal on.

 

[ban-all-sheds]

Knauf?

Xtratherm?

 

[sweeneyuk]

what about 100mm of rockwool wedged into the space?

i can prob get 75mm of celotex in before it infringes on the cables etc.

does the foil covereing protect pvc cables?

 

[ban-all-sheds]

From what?

Rockwool and PIR don't damage PVC, it's polystyrene that does that.

 

[sweeneyuk]

so the pir doesnt react with pvc in cable insulation, just thought pir was extruded poly & might still react. good to know it doesnt & was on phone with celotex earlier who also confirmed this.

Ga 3000 seems best bet, in 70mm but dearer than expected.
been searching & jewsons do recticel insulation in 75mm for £22 +vat.

anyone know of recticel? looks just like celotex & kingspan & guess they are all pretty similar being made of the same materials.

anyone getting a better deal on 70 or 75mm pir board?

bear in mind i dont have an account with any yet but will be doing so soon.

 

[freddiemercurystwin]

I would be gobsmacked if you cannot better any price from Jewsons! Not all insulation materials are the same despite outward appearances.

 

[ban-all-sheds]

so the pir doesnt react with pvc in cable insulation, just thought pir was extruded poly & might still react.

Different substance. Polyisocyanurate, not polystyrene.

anyone know of recticel? looks just like celotex & kingspan & guess they are all pretty similar being made of the same materials.

According to Recticel's website it's made of polyurethane, not polyisocyanurate, so not the same material.

You'll need to do some research into the differences, how important they are to you, and decide how much extra you're prepared to pay for them.

 

[sweeneyuk]

so i've had a look at pir vs pur & am getting conflicting info.

One site says pir has superseded pur & its main difference is its fire rating.

But speaking with selco who sell another brand they say pur is the new best thing not pir.

also they said that celotex is pur but i've only found ref to it being pir.

so whats best pir or pur?

both seem so similar but want to make the right choice & best price i've found is £22 +vat.

i've called:

builder depot
selco
jewsons
travis perkins
long & somerville
wickes
looked on ebay
googled

anymore stockist?

 

[hotrod]

so i've had a look at pir vs pur & am getting conflicting info.

One site says pir has superseded pur & its main difference is its fire rating.

anymore stockist?

http://www.sheffins.co.uk/contact.asp

Plus these guys are experts in the field of insulation so if you want advice listen to them.

 

[ban-all-sheds]

http://en.wikipedia.org/wiki/Polyisocyanurate

 

[ajrobb]

There is some doubt about the long term insulation of PIR. Its initial conductivity of 0.024 is much lower than a typical 0.04 for mineral wool. This is due to the blowing agent used in manufacture. However, this blowing agent will eventually leak away to be replaced by air over a number of years. After 5 years, its conductivity might be similar to mineral wool's.

It is therefore debatable whether it is worth the extra expense over mineral wool.

 

[ban-all-sheds]

Can't read that article.

How about Aerogel?