Insulation - foil faced or not?

[pilsbury]

What purpose does the foil serve? vapour control? reflection of heat?

Just ask as there seems to be a big difference in price. To be used for warm deck roof 120mm thick.

 

[Ian H]

How much for the foil ones?

 

[pilsbury]

Damn near £50. That's new. Seconds are hardly cheaper. However some non foil seconds are half that.

 

[freddiemercurystwin]

I use the foil as a handy mirror, to check my makeup.

 

[Ian H]

I use the foil as handy mirror, to check my makeup.

You probably look better in the foil than a normal mirror.

I've seen seconds at £36 but they are collection only from Preston.

 

[trevorbayliss]

I am just buying a load of insulation at the moment. All foil backed, so stuff like celotex/kingspan/recticel.

100mm 8x4 sheet = £33.31 plus vat.

50mm sheet £18.88 plus vat

25mm £11 plus vat.

There is a shortage of this insulation apparently due to a fire in germany where they make the chemicals which all the producers use for this insulation. Price increase of 17% coming in october apparently.

You could use the non foil stuff providing you lay a vapour plastic sheet layer.

 

[freddiemercurystwin]

You probably look better in the foil than a normal mirror.

You Bitch!

 

[Doggit]

You Bitch!

The truth always hurts, and this is where someone brings up the Jack Nicholson clip "You can't handle the truth".

 

[tomfe]

Theoretically you get a better uvalue with foil faced due to a: less radiated energy escaping due to the reflectiveness b: foil lessens the off gassing
In reality not much.

 

[Nozzle]

Although I think it's worse if you're trying to use a pipe/cable/stud finder and also worse for your house-wide WIFI signal!

Nozzle

 

[23vc]

This stuff is one of the few things I never use my local merchants or Travis etc for and always go online, the main ones at the top of a Google search have always given me delivery within a couple of days and the best price which the merchants can't get near ( for me)

 

[pilsbury]

Cheers for the replies.

New from the online merchants is £50/foil faced board

Seconds are £48/foil faced board (the lesser priced boards are not in stock)

Seconds that are non foil faced and appear to be 1/4 sized boards work out to the equivalent full board price of £25/board. Quite a saving but more of a faff to lay.

 

[SFK]

Pilsbury,
thinking out of the box, I was wondering if 130mm might be cheaper if 120mm is normal spec.
It wasn't, but I did find this guy in Altrincham selling 130mm for what I calculate to be £28.80 a sheet, no VAT, Plus shipping:
http://www.ebay.co.uk/itm/130MM-Ins...486012?hash=item1c91b29c3c:g:1jgAAOSwQTNZuRCv
SFK

 

[bernardgreen]

What purpose does the foil serve? vapour control? reflection of heat?

Reduction of signal strength for some wireless based equipment.

 

[John D v2.0]

Slight improvement in u value if it's facing into a void. The common thickness especially 50 and 100mm are much cheaper per M3, you could use a layer of 100 with 50 on top, or even 50 with 70 on top if you can get it cheap and don't have the space.