Flat roof insullation for refurbishment.

[harrymonkfish]

Hi there.

I am about to refurbish my flat foof with a fully adhered epdm membrane. But I also want to insulate as well.

At the moment it has a fibreglass covering and i will be using kingspan 100mm.

I know you can get special kingspan for this type of membrane, but you have to buy a whole pallet full, which is too much.

So this is my idea.

Leave the fibreglass where it is. Just clear the raised parts around the perimeter.

Lay down the insulation straight onto the old roof.

lay ontop of this some 11mm osb

screw down throught the boards and the insulation with some long screws.

glue the membrane down onto this new deck.

does this sound like a good idea?

all answers are much appreciated.

kind regards
harry monkfish

 

[SurreyRoofingEstimator]

Sounds fine to me, you could buy Kingspan TR27 which allows for the bonding of single-ply membrane directly on to it rather than over-boarding with ply (or OSB). You say a pallet full would be too much, is the roof very small, the TR27 comes in a 600x1200mm board size and there are only 3 boards in a pack, if you went to a local insulation stockist I'm sure you can just buy just the quantity you require.

You will need to edge the flat roof with a timber stop batten the same thickness of the insulation.

 

[Xenon]

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