Drilling through concrete and stone ....

[ray316]

l'm putting some post brackets onto a concrete/stone base in the front garden and need to drill down a good 6to9 inch . l have used a masonry drill bit and get a few inch into the hardcore and it will not go any further as l hit stone. At the moment l'm using a hammer drill, will using a sds drill and drill bit be any better or any suggestions will be useful..
Is there anywhere l could buy a 8mm sds point chisel so maybe l could break the stone/concrete hardcore up..

 

[Burnerman]

Go for a larger size mains SDS drill - maybe from the local hire shop if its a one off task, using larger diameter bits than usual. Get one with a roto stop and you can use it as a breaker, too.
John

 

[StephenW]

I wanted to fit 7 bolt-down metposts onto a concrete slab. That means 28 holes of about 10mm diameter.
I started with my masonry bit in my mains-powered hammer drill. After about 5 minutes I has made one hole about 25mm deep!
I went and hired a heavy duty SDS drill. It was like a hot knife through butter! - it drilled into the concrete as easy as drilling wood with a normal drill.
So yes, I think the SDS is what you need.

 

[cotswoldbuilders]

SDS drill, if your fitting clamp down brackets for the posts, ie the ones with 4no bolt holes, you dont need to drill that deep, use thunder bolts, probably 50mm to 75mm are ample, its states the drill size on the end of bolt, drill your holes and bolt down, they cut their own thread.
Ive used them on 100mm clamp downs, into 50mm slabs with no problems, even fitted them about 30mm from edge of slabs and they dont break out.

 

[ray316]

ok SDS drill it is ..
Also my other question if anyone knows ...Is there anywhere l could buy a 8mm sds point chisel so maybe l could break the stone/concrete hardcore up..

 

[cotswoldbuilders]

Never heard of a sds chisel point that small, smallet is about 20mm