Drill bit for Indian Sandstone?

[cb31]

I laid an Indian Sandstone patio a couple of weeks ago and need to drill through it so I can fasten down the pergola. I have an SDS Plus drill with a new 14mm bit but it is hardly going through it. I am not using the hammer as I am scared of cracking the tiles. I'm sure if I turned on the hammer it would go through it like butter but don't want to ruin my hard work. At this rate 16 holes will take all week and no doubt loads of new bits and upset neighbours.

Can anyone recommend an SDS drill bit that is up to going through 22mm Marshalls Indian Sandstone or do I just turn on the hammer and risk it?

[ahas]

I'd have thought a decent masonry drill bit would do nicely.

I use Dewalt Exteme2 and I think they're excellent for drilling through things when other bits would give up. Not to say you're using cr*p ones.

Failing that try drilling smaller pilot hole first and work your way bigger.

A quick Google suggests carbide tipped (dewalt extreme bits are) or diamond tipped.
https://www.hunker.com/12522530/how-to-drill-into-...

Depending on the thickness of your slabs I wouldn't use hammer function (Esp with a SDS) as risk of cracking. Just patience and letting your bit cool when it looks like it struggling on normal action.

[Lotobear]

I would try a tungsten carbide tile drill bit

[chadders74]

Same issue, bought SDS drill and straight through. Get off cut if lying around and practice, otherwise pop to local merchants and grab a spare piece.

[pquinn]

If you want to do it 'carefully' then use a diamond tile drill (the hollow sort like https://totaltiles.co.uk/diamond-tile-drill-bit-14... ) and bore a hole through it. A lot less material removal and would cut through something like sandstone with no problem and no hammer action.

Not the cheapest drill bits but they do work. There is a bit of technique needed so you don't skid the drill around but easy enough to learn. You'd probably want to wet drill it, but check the instructions for the bit.

[Carbon Sasquatch]

pquinn said:

If you want to do it 'carefully' then use a diamond tile drill (the hollow sort like https://totaltiles.co.uk/diamond-tile-drill-bit-14... ) and bore a hole through it. A lot less material removal and would cut through something like sandstone with no problem and no hammer action.

Not the cheapest drill bits but they do work. There is a bit of technique needed so you don't skid the drill around but easy enough to learn. You'd probably want to wet drill it, but check the instructions for the bit.

This would definitely work, I just did some holes in 20mm porcelain tiles with a similar one from Screwfix - not SDS though, just a regular fit

The easiest way to do it is to get a scrap bit of wood & drill a hole in it the same diameter - I bought a paddle bit at the same time specifically for this. You then hold the wood (or kneel on it) and use it as a guide to stop the bit wandering until its started cutting into the tile / slab.

[cb31]

Thanks everyone, my drill bits are probably crap as they were from a multipack. I got sick of getting nowhere and used the sds hammer but not on full power. It went through it a lot faster and I'd imagine if I gave it the full beans it would go straight through. Drilled 5 holes out of 16 so far and did crack one slab in the corner but I started on the least noticeable side so it doesn't matter.

My bottle has run out though so I'll stick where I am and go and get one of those dewalt extreme bits from screwfix, I can't face damaging the obvious slabs at the front. Cheers

[robwilk]

https://www.screwfix.com/p/tile-holesaw-17mm/5655v

I would try one of these with a little water

[ahas]

cb31 said:

Thanks everyone, my drill bits are probably crap as they were from a multipack. I got sick of getting nowhere and used the sds hammer but not on full power. It went through it a lot faster and I'd imagine if I gave it the full beans it would go straight through. Drilled 5 holes out of 16 so far and did crack one slab in the corner but I started on the least noticeable side so it doesn't matter.

My bottle has run out though so I'll stick where I am and go and get one of those dewalt extreme bits from screwfix, I can't face damaging the obvious slabs at the front. Cheers

If you're not in a hurry amazon is usually best priced for dewalt extreme drill bits. Be interested to know how you get on

[stevemcs]

Try here

https://www.atsdiamondtools.co.uk/

I've got some bits for 20mm porcelain and they go through them like butter.

[dhutch]

Assuming its mid paver not stupidly near the corner or something I would turn on the hammer action and it will breeze through it, especially if it's a new patio and you have a few spare pavers just on the 1 in 100 chance it doesnt like it.


Daniel

[Aluminati]

Are they fully bedded or blobbed ?

[PositronicRay]

As an alternative idea.

How about sitting each leg in a large pot, (different styles on each corner maybe) and pouring some concrete in.

Should be heavy enough, plus you could always move it if desired.

[Skyedriver]

Interested in this thread as I have a precast concrete step (pressed concrete like a kerb or channel block) to drill for a handrail

[Simpo Two]

robwilk said:

https://www.screwfix.com/p/tile-holesaw-17mm/5655v

I would try one of these with a little water

That's looks good to me.

[cb31]

Aluminati said:

Are they fully bedded or blobbed ?

Somewhere inbetween, all around the edges with a cross in the middle. I know it should have been fully bedded but I was mixing by hand and it was onto a concrete slab. Couldn't get a mixer due to lockdown.

I bought the dewalt extreme drill bit today and will give it a go tomorrow and post an update

[cb31]

PositronicRay said:

As an alternative idea.

How about sitting each leg in a large pot, (different styles on each corner maybe) and pouring some concrete in.

Should be heavy enough, plus you could always move it if desired.

Unfortunately the patio isn't big enough, planters around the pergola legs would make it too tight for the dining table to get easy access.

[hutchst]

If you're going to bolt it down to a couple of paving slabs, at the same time you should fit a GPS chip so you can find it easily next time the wind blows.

[Carbon Sasquatch]

hutchst said:

If you're going to bolt it down to a couple of paving slabs, at the same time you should fit a GPS chip so you can find it easily next time the wind blows.

It says 2 posts up that there's a concrete slab under the paving, so hopefully it's being anchored to that...... 14mm would be a wide hole if it was only going 22mm deep.

Edited by Carbon Sasquatch on Tuesday 23 June 07:31

[cb31]

Just to tidy this thread up got a final update now I have finished. I got the dewalt extreme drill bit and it was no different to my existing bit, it would only go through the sandstone with the hammer action. I managed to damage two slabs but it is hardly noticeable now as the brackets cover most of the damage. Due to this I only put 2 holes in one corner and 3 in another instead of 4 as I was too worried about causing damage where it would be visible.

Unfortunately once I drilled into the concrete base slab it seemed to disintegrate so the fixings aren't exactly secure as I would like and some are only attached to the sandstone slabs. The concrete slab was pre-existing when we bought the house so I had no idea how useless it was.

So I've ended up with a great looking installation that isn't as secure as I would like but as it has just been resting on the previous uneven patio for a year with no problems I'm not too worried. If a bit storm is forecast I'll just run a rope to the fence and tie it down for peace of mind.

In hindsight I should have tested the concrete slab before laying the sandstone but you live and learn. Sourcing a diamond tile core drill bit would have been better too but I was too impatient. It isn't as good as a professional job but I did it myself and will take great pleasure over the years knowing I didn't just throw cash at someone. I still need to finish the edging off but that can wait a few weeks. Cheers for everyones help.