Flat roof fixings

[Jan1979]

Hi. Please could someone please provide some advice on new flat roof fixing. I am current building an extension with a flat roof. The roof will be of the following make up.

175mm roof joists.
Timber firrings
18mm ply deck
VCL
125 celotex insulation
18mm ply top
EPDM membrane

The part that I'm stuck on is how and what do I use to fix the ply top and insulation to the roof deck?

 

[cotswoldbuilders]

Twistfix, Insofast flat roof Insulation fixings.

 

[Jan1979]

Hi. Thank you for the reply. Every where I read talks about using these fix for insulation or insulation with 6mm ply already bonded on the insulation. Can these be used when the is 18mm ply on top of the insulation?

Would they require a poilt hole? Would the dome head show through the EPDM membrane?

 

[cotswoldbuilders]

You can use the dedicated bit in a hammer drill for easier fixing,


Yes , any imperfection will show through the rubber.