How to fit back boxes in thick wall boards?

[greeny]

Hi,
Help please.
I have to first fix back boxes on to a wall which will be having 15mm battens and 57mm thick insulating boards . Should I use metal backboxes with a suitable wooden backing in order to bring the back box level with the front of the wall,
or will I be able to use plastic dry lining boxes and somehow push the lugs into the insulation material. The lugs will not be able to fit behind the insulation board because of its thickness.
Greeny

 

[gaffer]

use fast fix boxes and once youve cut out ,use you padsaw to make a small hole between the plasterboard and insulation to take the lugs of the box.

 

[Guest123]

If you use the extra deep dry lining boxes this will help as you wont need to cut away as much of the sides so it wont effect the strength of the fixing as much.

 

[A-Non-eMouse]

cut your box hole then use the back of a claw hammer to chip away at the sides of the plasterboard. be careful though, no going back if you chip to much away. theres a knack like all these things.

 

[Sintra]

Extension boxes are also available for metal flush boxes. 25mm 35mm & 45mm available.

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