Core Drilling a 900mm Stone wall

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Any advice on the best way to get a 110mm waste pipe through a 900mm deep stone wall? I have core drill, but never core drilled so deep before.
 
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You will need extensions for the shaft (unless you have a long bit).

Assuming a diamond tipped bit: (Wouldn't want to do this with percussion tbh)
Use water. Not too much as you will polish the bit, not a little as you will burn it out.
Start off level and true.
Do not let the bit spin on the stone, you need to give it some effort. Again, not too much else you will burn the bit out.
Once you reach the end of the bit, break off the core with a chisel and pull it out, if it's stuck, use a welding rod,
Make sure you have a firm footing incase the bit stalls.

Limestone is ok to drill.
Granite or washed river is an absolute bugger. If you are hiring a bit, make sure to tell the shop what stone you are drilling as you need a softer matrix for harder stones.


Oh, and wet the wall first. it makes cleaning up far easier.
 
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Many thanks, sounds fun, it is Sandstone as most cottages up here in Scotland are built.
 
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Chances are a 900mm thick stone wall will be rubble filled .
No easy way I'm afraid you may get lucky but normally a world of pain.
If you want to try coreing all way through then a drill intended for core drilling a must .
I've seen this sort of job take anything from 20 min to a day and a half.
 
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Chances are a 900mm thick stone wall will be rubble filled .

It can be near impossible to core drill through a rubble filled wall if the mortar holding the rubble has crumbled. Each bit of rubble moves away from the cutters.

I needed to get a replacement joist into place by going through the wall. Once the one stone in the face of the wall was removed the rubble could be removed by hand

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Many thanks, sounds fun, it is Sandstone as most cottages up here in Scotland are built.

Sandstone will be really easy to drill through.
use a diamond core drill, it won't like percussion.
If the wall is filled, just go at it from both sides (you need to measure accurately though)
 
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or use a long drill to make a pilot hole as a guide ( it may get deflected by a hard stone )
No,

You are better off measuring. Drilling pilot holes that long isn't accurate as the bit goes askew.
You also risk blowing off facings on the other side of the wall.
 
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Is there any merit in chasing the drill through with some short bits of pipe of similar size to the core? In other words drill in a bit, push the pipe in behind it to support the rubble.

I once drilled through a farm building wall around that thick, just to insert a cable - nightmare with falling rubble infill.
 
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Sounds like I am to have fun, thanks for all the input. I have dimond core drills, and a drill with a clutch :)
 
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As bernardgreen explained - a rubble filled wall needs the rubble centre handpicking out.

My view is that:
In a 900mm sandstone wall its probable that only the outer and inner facings will be core drill'able
 
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Dismantle the fascia stone (enough to be able to work) carefully and preserve. Hammer out the hole. Pipe through and re-build from the inside out.
 

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