7 inch round hole through exterior wall for flue - safe?

[pjsmith]

Hi,

I need to get a hole made through my ground floor kitchen wall for a 7 inch diameter flue pipe.

I've looked all over the web and people seem to just get busy with the drill.

My concern is, the hole needs to be at a 45 degree angle, not horizontal through the wall. My walls are 1930's solid 13". At 45 degrees, that's a lot of material out of a ground floor wall (1st floor above). I can't see a single example where anyone has ever installed a small lintel or similar for such a hole, but I'm not feeling safe about it! The diamond driller I spoke to was happy just to get busy. Never brought up the concern of if it was safe.

Can anyone advise?

 

[saladdays]

It can be done at 45 degrees. Click below and scroll down to see pictures:

http://thegreenlivingforum.net/forum/viewtopic.php?f=21&t=108310&start=20

 

[pjsmith]

Hi,

Thanks for the reply. I read many threads like this. No-one seems to do into any detail of if such a hole can effect the wall.

No-one has concerns about making a 45 degree 7 inch round hole through a 13" double block solid 1930's load bearing exterior wall?

 

[noseall]

You are unlikely to be able to drill a 45° hole through a wall with a core drill.

You best bet is to remove enough material for the flue pipe to be installed comfortably then brick it in.

 

[footprints]

Before fanned flues, boiler and water heater flues were about 12" square all that went through them was a thin steel liner I have never seen any wall collapse as a result.
Google "self-corbelling effect" even if a lintel above a 2 or 3 foot window fails only a triangle of bricks above starts to drop.

 

[Nige F]

Hi,

I need to get a hole made through my ground floor kitchen wall for a 7 inch diameter flue pipe.

The diamond driller I spoke to was happy just to get busy. Never brought up the concern of if it was safe.

?

Then he will save you a lot of hassle cutting out and reinstating . I presume he will fix a jig to the wall and simply drill the correct size and angle . Wet or dry drilling it`ll be messy ,