Core hole through random rubble wall

[orbit123]

Hi,
anyone ever cored a hole (for waste pipe 125mm) through a random rubble wall - about 2 feet thick?

The outer and inner stones are too big to remove which seems like a common solution - bit worried that once I've cored the outer stone the random rubble middle will be an issue and jam the drill.

I'd hire a dedicated core drill with clutch etc. Only ever done this on brick/block but this is whinstone which from the pilot hole is like drilling metal!

Cheers.

[spikeyhead]

If I had to try this myself then I'd core drill the inner and outer, and just trim the inside away with a long masonry bit.

[R1 CKY]

I've done it a few times in 4 inch for boiler flues. It may take you a few hours.

Once you have gone through, don't pull the bit straight out. Put your waste pipe in as someone pulls the drill out, bits of stone will fall down and block the hole, they can be bugger to move aswell.

[TheEnd]

Maybe drill through one skin, inject some of that expanding foam, and re-drill later once the insides are all stuck together.

[Flintstone]

I've heard of all sorts of wall but never a random one. Does the universe just throw them up out of the chaos?

[thinfourth2]

How about hiring a core that is 130mm internaly then you can put the core through and then stick you pipe inside the core and pull the core out leaving the pipe inside

[astroarcadia]

Done this exact job at my house recently.

16mm pilot hole straight through then 110mm core from outside. Just fish out the loose stone in the centre of the wall by hand as hit it. The drill will probably let you know by jamming the chuck. Took me a good hour.

[astroarcadia]

Done this exact job at my house recently.

16mm pilot hole straight through then 110mm core from outside. Just fish out the loose stone in the centre of the wall by hand as hit it. The drill will probably let you know by jamming the chuck. Took me a good hour.

[orbit123]

thanks to all. One other tip I read was to drill a couple of small holes just above the core and put some rebar through before coring. Idea was to stop endless amounts of the rubble falling in. This would all depend on how fine the rubble is I suppose.

I like idea of feeding the pipe through from the other side as core bit is withdrawn but wall is 2 ft and the core bit will likely be 150mm.

I've 4 of them to do though so probably know works best by end of the 4th!