2 metre drill bits

You really need a mole... If you start under the floor and drill out to the clay, if it's firm (big if!) you might be able to bore the rest of the way using something like an auger or an old-fashioned 1 or 2" diameter wood bit, mounted somehow on the end of a broomstick.

Are you certain there's no drains crossing the space?

In article , Andrew Gabriel writes

Assuming you're drilling through into open space (under floorboards, for example), and the soil is soft enough, you could try simply hammering a length of 22mm copper pipe (or steel pipe of similar diameter) through. I've done this in the past. Leave the end of the pipe open so the edge cuts its way through the soil; if you cap the end you just compact the soil and make the job harder. The pipe will fill with soil; later, to clear it, you can either push the soil out using a rod or use a hosepipe to wash it through.

I have a 300mm long 25mm dia drill and a similar length extension that screws onto the end of it, that I used to drill through both sides of a disused chimney. The extension piece could take further extensions, giving a theoretically unlimited length of drill.

Colin Bignell

In article , Andrew Gabriel

I did similar to get an oil pipe under a concrete path. I used 1" steel pipe and sharpened the wall of the leading end to help it cut through. My problem was I needed a trench the width of the path plus hammering space to work in and didn't have it. I had to cut the length of pipe into three and weld on the next length after the first was hammered in. I did find that rotating the pipe whilst hammering helped. It worked, but but didn't come out quite where I would have liked and I was only going through subsoil.

Mike

I have a 1m long 25mm bit, but I need to go through fractionally over 2m, and ideally at 35mm (planning on using 32mm MDPE as ducting).

I wonder about attaching a drill bit to the end of the lining pipe itself, drilling through, then chopping the drill bit off afterwards, leaving the lining pipe in place ready to run cables through. 2m through anything seems like rather a lot, though; I know the drill bits in my local DIY sheds top out at around 1m.

OP, will the patio blocks not lift up so you can just put a trench in?

I like that idea. The lawn slopes down quite steeply in front of the patio, so wouldn't need much hammering space. Might be easier to hammer through from the inside, having done a core bore through the wall from the inside, or taken out a couple of bricks first.

Where to get steel pipe? Don't recall seeing in plumber's merchant. Scaffold pole (just under 2" dia?) may be a way, but rather heavy. I may have a scrap piece of 1/2" or 3/4" to try first.

Not sure how one would "aim" it though, water level?

En el artículo , Andrew Gabriel escribió:

Like another poster said though, 'ware the drains and other services.

On 13/08/2012 23:35, Andrew Gabriel wrote: ...

PipeCenter deal with larger pipes than most plumbers' merchants, although you may need to order steel pipe.

Colin Bignell

In message , Andrew Gabriel writes

Bit of 1" water barrel?

Plenty on my *possibles* pile:-)

regards

There are drains there, but they're all significantly deeper. Actually it was the manhole which caused me the problem. I had originally intended to route the cables in the gap between the manhole and the end of the raised patio. It turned out that the manhole is much larger on the outside than it is on the inside, and far from being a gap, the outside of it goes well under the end of the patio.