Any advice on increasing 4 inch extraction hole to 6 inch

[MickSmith5824]

Hi All

As above need to core drill wall. Client wants to increase extraction hole size, any tips for going about this. For what's it's worth I use a marcrist cutter. I would usually use the smaller one as a guide but cannot attach both for this purpose. Thanks

 

[SparkySy]

I have in the past used a piece of ply screwed to the wall with the larger size hole already cut in it as a template, once the cutter is in the brickwork it will usually guide itself and the ply can be removed. I have had to leave the ply in place before if the wall is particularly carp.
Sy

 

[Tony Way]

Hi All

As above need to core drill wall. Client wants to increase extraction hole size, any tips for going about this. For what's it's worth I use a marcrist cutter. I would usually use the smaller one as a guide but cannot attach both for this purpose. Thanks

If you don't need to centre on the original hole you could try what I do, start with the 6in core drill resting on the lower edge of the hole and carefully bring up to vertical as it starts to bite, or get some 1/2in ply (or some such), cut a 6in hole, screw it to the wall around the existing hole and use it as a guide.

 

[Tony Way]

Too damn slow... - As sparkySy suggests

 

[MickSmith5824]

Thanks chaps all helpful probably go with the ply