Core Holes in a wall - How Close Is Too Close? (Ed.)

[pogrady]

Hello.

I have had a new cooker hood installed. It requires a 6" duct but has been installed with a 4" ducting reducer. Also, the external wall hole is approximately 10cm above the hood, but the installation guide recommends at least 60cm vertical run before being vented outside, which in my case is 90 degrees to the hood. I want to drill a 6" hole above the existing 4" hole. Questions are i) how much clearance do I need between the two holes so that I don't compromise the strength of the wall, and ii) do I need to fill in the existing 4" hole?

Thanks,
Paul

 

[jj4091]

Personally I would try it with what you currently have. I very much doubt making either of the alterations (bigger hole or higher up ) will have any effect

 

[Ivor Windybottom]

If you're drilling above then it won't make much or any difference. Alongside it would be more of an issue.

But I can't picture the situation from your description, a photo or diagram would be helpful.

I can't understand why a short duct would be an issue, it would just reduce the potential for condensation which is a good thing.

Defiinitely fill the unused hole, together with the cavity and insulation.

 

[Murdochcat]

If you are going straight out of the wall and there are no lengths of pipes involved I would use the existing 4" hole .