Drilling through granite stone wall?

[Burdekin]

Morning,

I want to drill a 30 to 40mm hole through a granite stone wall. I got a quote of £250 so thought maybe I could buy a diamond core drill bit and do it myself, I have a SDS drill already. Would something like this with an extension drill a 300 to 400mm hole? https://www.screwfix.com/p/erbauer-diamond-core-drill-bit-38mm/57772 If not is there something I could buy at a reasonable cost?

 

[angellonewolf]

can you find anoher way ?

years ago( 30 years so there may be better drill bits around now) work mate spent hours drilling a hole untill the caretaker come round the 2nd day and said you wont drill that its granite and it 6 feet thick

i think he got about 6 inches in to it even hired a hilti drill as well and only got that far


if no way to get round it might be worth getting some one in a local company round here when i called them said they can tag it on one of there blokes days and if i paid cash it was that not expensive (this was 20 years ago but the cost of a good drill bit and possable hire of a core drill might be the same cost ?

 

[Burdekin]

can you find anoher way ?

years ago( 30 years so there may be better drill bits around now) work mate spent hours drilling a hole untill the caretaker come round the 2nd day and said you wont drill that its granite and it 6 feet thick

i think he got about 6 inches in to it even hired a hilti drill as well and only got that far

I didn't have much hope doing it myself to be honest. Asking on a local facebook page for some other blokes who do it. The place is made of granite, must be a few folk about that can do it.

 

[angellonewolf]

a quick google does say a quality dimond core bit will drill it but you drill for 10 seconds and then stop but id say you will need to drill slow prob more slower than a sds will drill

im sure there will be some on here that lives in a granite house that has experance

 

[Kayos]

Granite usually needs water cooled diamond core.
The price quoted isn't bad, would be a similar price for a much bigger hole as the setup is the same

One firm also charged me the tip wear on top of the drilling charge, so watch out for that

 

[prepman]

Core drill, slow speed and water...doddle. Granite decomposes to porcelain clay. Quarry tiles are harder stuff.

 

[dobbslc]

I've got the set of those core drills, they have been pretty good on my house walls, they are brick but it's very hard brick.
Slow and wet will get you there!
@Pete. Might know better if that Erbauer bit is up to a granite wall though.

 

[Burdekin]

Thanks. Found another guy on Facebook that is much more reasonable.

 

[Dee J]

For me, on my own site, with old core drills and other gear I've got about, I'd give it a try. You're looking at less than half a metre, so you're less likely to encounter a random stone/muck core. But if you're gearing up just for this one job, and have no future use for the kit, then £250 isn't bad.
But there's granite walls and granite walls too. Is thus firmly bedded dressed stone, or random rubble in crumbling mud. If the latter, then removing a stone or two can be the better route.

 

[cheb]

I drilled two 100mm holes through 1200mm of Lewisian gneiss, a similar stone. It took a long time with an SDS hammer drill using TCT core bits and diamond bit. The diamond bit cut better on hammer. I know you're not supposed to but it got the job done quicker. As long as there was a tooth on the core bit it would cut.

Very very dull work, I spread it over a couple of weeks to lessen the possibility of vibration induced health problems.

 

[Nomad]

Not granite but I spent a couple of years as a plumbers helper - often boring holes through outside walls for drainpipes etc.

Advice from the plumber was that bigger holes (+ 100mm ?) you need a drill with a clutch. For 30-40mm I'd try a normal drill but be prepared in case it jams, use a wrist support if the drill has one.

 

[DAPPH]

This time last year I put a 76 mm hole through a heavy concrete cavit block wall for my mancupboard heater , and a 35 mm hole for eh air intake for he burner and another the same size for the exhast pipe

Her's how I did uit . it/s quite different from going through sand stone , limestone or light arieated concrete blocks .

Put a long thin pilot drill through first so the cocr drill pilot can follow the hole right through the wall . Core drill from both sides to get a nice hole one each side . Beware of the core drill pilot drill coming loose and sticking in the hole . ( Even using brand new parts from Screw Fix )

Don't let the SDS hang by its weight on the drill bit adaptor at the chuck end they are very thin and they break far too easily if you do .

On a hired bit & drill the core drill kept coming loose I had to separate the core drill and the holder and clean them up for an hour or more to remove deep scores & ridges on the contact faces as the drill would not seat in the adaptor properly . Used water & medium wet & dry before the core pilot drill would stick in the holder .

Make sure your SDS has a slow speed & a clutch , don't use hammer , let the drill do the work don't try to force it into the granite , a light gentle pressure is best , keep bringing the core drill in & out and vacuum out the dust / crud if possible .

If the wall is infilled with rubble be aware that lumps often fall down behind the back face of the core drill making extraction difficult to say the least.

Had to disconnect the SDS and pop on a long 10 mm drill bit to drill into the fallen stone first then drill on hammer the chunks to break down stones that had fallen down stopping me pulling the core drill out . On thick walls I used a 15 inch long round drift punch made from high carbon steel to put in the core drills pilot hole every two to three inches and give it a firm but not heavy tap with a small lump hammer to split the column/core of stone that formed as the cutter bit into the stone . After a while if you don't remove this island of stone your core drill rear end will rub on it and you cant drill any deeper .

 

[DAPPH]

Not granite but I spent a couple of years as a plumbers helper - often boring holes through outside walls for drainpipes etc.

Advice from the plumber was that bigger holes (+ 100mm ?) you need a drill with a clutch. For 30-40mm I'd try a normal drill but be prepared in case it jams, use a wrist support if the drill has one.

A drill with a side handle is essential be it a heavy or light SDS drill

 

[Burdekin]

I had three other guys all about the same price; £120 to £130. So getting it drilled on Monday.

 

[Burdekin]

This time last year I put a 76 mm hole through a heavy concrete cavit block wall for my mancupboard heater , and a 35 mm hole for eh air intake for he burner and another the same size for the exhast pipe

Her's how I did uit . it/s quite different from going through sand stone , limestone or light arieated concrete blocks .

Put a long thin pilot drill through first so the cocr drill pilot can follow the hole right through the wall . Core drill from both sides to get a nice hole one each side . Beware of the core drill pilot drill coming loose and sticking in the hole . ( Even using brand new parts from Screw Fix )

Don't let the SDS hang by its weight on the drill bit adaptor at the chuck end they are very thin and they break far too easily if you do .

On a hired bit & drill the core drill kept coming loose I had to separate the core drill and the holder and clean them up for an hour or more to remove deep scores & ridges on the contact faces as the drill would not seat in the adaptor properly . Used water & medium wet & dry before the core pilot drill would stick in the holder .

Make sure your SDS has a slow speed & a clutch , don't use hammer , let the drill do the work don't try to force it into the granite , a light gentle pressure is best , keep bringing the core drill in & out and vacuum out the dust / crud if possible .

If the wall is infilled with rubble be aware that lumps often fall down behind the back face of the core drill making extraction difficult to say the least.

Had to disconnect the SDS and pop on a long 10 mm drill bit to drill into the fallen stone first then drill on hammer the chunks to break down stones that had fallen down stopping me pulling the core drill out . On thick walls I used a 15 inch long round drift punch made from high carbon steel to put in the core drills pilot hole every two to three inches and give it a firm but not heavy tap with a small lump hammer to split the column/core of stone that formed as the cutter bit into the stone . After a while if you don't remove this island of stone your core drill rear end will rub on it and you cant drill any deeper .

I feel guilty that I just went and got a guy after all your effort. Good bit of advice.

 

[RWD3M]

I had three other guys all about the same price; £120 to £130. So getting it drilled on Monday.

That's the price you pay for living in the Granite City!

 

[RaceDiagnostics]

This guy was £150, and worth every penny.

 

[Brad93]

You won't drill it with an SDS.

You need a proper coring drill and possibly water

 

[brightspark]

You won't drill it with an SDS.

You need a proper coring drill and possibly water

correct even a good quality norton core bit in a 1500 w core drill dry wont touch it. been there and got the teeshirt and both tools

 

[Pete.]

You will 100% need water for drilling granite. That slotted drill in the link is designed for dry cutting but you can't dry cut granite. You could wet cut it by taping over the slots though. It's a 3-segment drill bit which means it would be well suited to wet cutting harder materials with a lower powered machine even though it's probably got budget-level concentration of diamonds in it. Usually a 1.5" wet cutting drill bit would have 4 segments. The hardest part about using that drill horizontally will be getting the water to the cutting face. Granite being so hard will have the teeth glowing in moments.

Would I attempt it - 100% yes. I'd expect to have to dress the teeth with a file a few times though, and I'd expect to get very wet using a DIY lash-up for the water feed.