Increase Wall Vent Dia

[diynot]

Hi all,

I have about 120mm dia (four and a half inch) circular vent hole in my kitchen wall.

The issue I am faced with is that Most of the vent kits are either 100mm, 125mm or 150m.

The vent is for extractor hood. Manufacturer recommend min 120m but prefer 150mm for maximum extraction.

What should I do? Do you think I should use a reducer and settle for 100m vent.

Or should I increase the dia, is it possible to increase now that a hole has already been cored though two course of brick wall?

 

[lame plumber]

core a 150 hole its in the instructions that is the size.

 

[Reg Man]

Don't you do what the manufacturer recommends?

 

[Simon F]

if you don't have the correct size core bit,
or can't get the hole to stop wobbling all over without the drift guide.:86:
Then just resort to stitch drilling around the existing hole and chisel out the surplus,
it should come out easy enough with an existing hole already there...:73:

 

[albatross]

Screw two horizontal wooden battens 150mm apart above and below the hole. Screw two more vertically to the first two creating a 150mm square frame. Put 150mm core drill in it and pull the trigger.