How do I make a neat hole through a 60cm weall for a combi flu pipe

My early victorian building has a nice stone facade covering what looks like a messy mix of mortar and rubble.

I want to fit a combi boiler and need to drill a 10cm hole for the flu pipe. How can I neatly cut such a hole through this type of wall ?

My neighbours did this recently but it seemed that the builder took three days and from the appearance and size of the resultant hole he must have done it with a pick axe! I would like to be somewhat tidier.

Reply to
Jo
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With a diamond core drill. I beleive you can hire these. Otherwise you'd need around 350+ for the gear.

Maker a pilot hole in to out and then core the hole out to in. You'll want a 107mm drill.

Reply to
Ed Sirett

Something to consider here is that when the core bit breaks thru on the far side it can cause the surrounding brickwork to fragment a little.

I have found it is better to drill the small pilot hole right thru, then apply the core drill from both sides, so that the large hole created by the core drill meets in the centre of the wall (or cavity). That way you get a nice clean hole both sides requiring only minor reparation.

In case no-one else mentions it, be aware that using a core drill can cause a lot of fine powder dust. SWMBO can be useful during drilling operations holding a vacuum cleaner hose just under the drilling area.

Andrew

Reply to
PoP

What sort of stone is it? My house is uncoursed random limestone, 2 foot thick, and one problem with using a core drill as suggested is that although the inner and outer faces of the wall are firmly mortared in place, the middle of the wall is loose rubble fill. I can see this loose fill causing problems for any drill. When my boiler went in, I removed the stones to make the hole then rebuilt around the flue (with quite a bit of expanding foam in the middle. The hole wasn't that much bigger than the flue though and was probably around a mornings work.

Reply to
John Armstrong

Hire a dry diamond hole cutter with extended arbor and sds drill machine or engage a man who has one. Where are you?

Reply to
John

Good point - rubble fill walls are a nightmare when encountered in these circumstances. Fortunately they aren't too common.

Reply to
John

Thanks for all the tips.

What is an 'SDS' drill ?

Reply to
Jo

SDS stands for splined drive system (CMIIW), but "SDS drill" tends to mean beefy drill that will bash it's way through concrete and stuff in a way that normal hammer drills can only dream of.

Cheers Tim

Reply to
Tim Sampson

Come on, don't understate the capabilities of the SDS drill ;)

PoP

Reply to
PoP

Just for information! maybe a bit expensive for a small job...

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Reply to
Abdullah Eyles

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