Cooker hood - incompatible hole/spigot/pipe diameters

[Steve]

I want to fit a cooker hood outlet and bought a kit for this.

The outside vent has a spigot of 125mm external diameter. The thickness of the flexible pipe that fits over it makes the overall diameter a bit bigger - about 129mm.

The hole's diameter is 127mm which I think is a standard core drill size. So the spigot plus pipe is too big for the hole. If I force the spigot and pipe in, it would be very tight and damage the pipe.

As far as I know, the outlet and pipe are standard sizes - but seem incompatible with the standard size hole.

Can anyone advise where I'm going wrong and/or any good solutions (preferably not involving enlarging the hole!).

Thanks

[meow2222]

Cutting a few slots in a solid pipe enables it to squish in a few mm. Then you reseal it by wrapping the exposed slotted section with duct tape. There are other ways too.

NT

[Steve]

Thanks NT - great idea.