Size of hole for 60/100 flue.

[Ant1]

I need to make a hole for a 60/100 flue for an Intergas Rapid 32 boiler which is soon being commissioned.

The flue will be going through a plasterboard, PIR insulation board and cladding.

What is the contentious regarding the diameter of the hole for 60/100 flue going through the above material?

Can I just do a 10 cm hole? Or will it be too tight and need to make one slightly bigger for expansion? i.e. 10.5, 11cm?

Thanks.

 

[muggles]

127mm is the norm.

 

[Madrab]

Yup +1 for 127mm - always good to have some wiggle room or if the boiler needs fall back on the flue.

If you get really good and a straight flue is ok then 117mm can be used but there's no room for error and wouldn't go any smaller.

 

[Ant1]

Thanks both!