How squidgy are space blankets?

[Golaboots888]

Hello

I'm looking to insuluate my garage roof. It's made from corrugated bitumen sheets which get cold and water condenses underneath.

Space blankets are on bogof at wickes at the moment and come in 400mm width at 150mm depth.
Ideally I need 500mm width and 100mm depth. As It's effecetively an upside down loft floor I would have to put boards underneath the insulation to hold it up.

What are my chances of squishing the blanket to required size?

Alternatives are the foil type stuff which is more expensive and somehow seems worse. Otherwise I could get some normal rockwool type stuff cut it to size and board underneath again.

 

[Deluks]

I was in Homebase t'other day. They had 100mm space blanket. Also on bogof.

 

[GoingDigital]

space blankets are basically normal loft insulation in a plastic bag with a foil coating on one side. So they are basically the same squishiness as normal rock-wool.

Personally I have found Kingspan/Celtex boards to be the best invention for putting in places where other insulation would have to be secured. They are rigid boards you cut them to fit between the timber and with a bit of foil tape it all just stays where it is put.