How to reduce the size of a hole on a brick wall?

3simon · Feb 13, 2021 6:04 pm

Hi guys, I've got an existing hole on my external brick wall for the rangehood vent (pic below).

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I'll be replacing my rangehood, and hence the ducting and the metal box within the hole will be removed and replaced with new ducting. I will also be buying a new vent to cover the existing hole, like the one below:

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The problem is the dimension of the new vent doesn't completely cover the existing hole. i.e. the hole is bigger than the vent..

How should I fill the 'gap'? Should I mortar to make the hole smaller? If so, how do I mortar the top? I imagine gravity will want to make the mortar fall before it has a chance to set?

Thanks in advance!

Bimbob · Feb 14, 2021 3:56 pm

colorbond flashing beneath the vent and around the penetration.

Be sure to seal appropriately.