Increasing rafter depth for PIR insulation

[benno1234]

HI,

Is there an BC accepted method for attaching 2x2 rafters to the underside of the existing 4x2 rafters to get the required depth to allow for 100mm insulation and the 50mm air gap? At some point I'd like to get it fully approved and don't want to have to take steps back.

Thanks

 

[tony1851]

Yes, you just screw 2x2 to the undersides of the rafters (up the slope).

 

[benno1234]

@tony1851 Thanks, standard wood screws every meter?

 

[catlad]

I would imagine you will need about 5 in every length.