Drilling Help

[aaront]

Need to drill a hole approx 1.25" in diameter & 5 feet long - through brick, concrete & clay. This is to put a 25mm water main through in its sleeve.

Anyone know if this can be done with a drill & extension bars? Or is there another way? The guy at the local HSS shop says they dont have anything that can do it - you boys/girls are my last hope before I have to dig a trench through my victorian tiled pathway.

Cheers.

 

[cobweb]

If understand you correctly you need to drill under your path?

If this is the case I can’t see how you would drill a horizontal hole under your path without first digging a pit (at both ends) to give you the vertical planes you’d need to start off the hole and finish it.

As for drilling the hole…

I would think that a specialist drilling company, something like a diamond drilling outfit, would be able to help but at a hefty price.

Otherwise, and this supposes that you do have a way to access a vertical face to drill into below the level of your path, you would have to jerry rig a boring bit.

You could buy a diamond tipped bit similar to a forstner bit and have the shank welded onto a 20mm steel bar and file/grind four flats on the end to allow it to be held in the chuck of your drill…

(A small steel fabrication company would be likely to help you with this…there’s a decent one just off the 406 at New Southgate behind the new garage)

At this point I should say that I doubt a “domestic” type hammer drill would have enough power to achieve a five foot bore, and you’d probably need a decent SDS type tool…but HSS have these or you can buy a quite cheap one from SCREWFIX.co.uk

Over such a length your problems are going to the effective removal of the considerable waste and heat generation (especially when cutting the brick and concrete)…

As it’s a hole, and the kit would be jerry-rigged, you couldn’t really run a water cooling pipe along the bore as the there wouldn’t be space to allow it…so it would have to be a very slow cut rate with frequent “pullouts” to clear the waste.

Is it not possible to lift only those tiles along the line you want, dig a narrow trench (say 40mm wide), lay the pipe, backfill, tamp, and then re-mortar the tiles in place over the top?

 

[aaront]

Cobweb

I have already dug a 600mm trench in the front garden so I know where I want the hole to come out and I have taken the floorbaords up in the front hall, under the front step are 2 courses of bricks which is where I want it to emerge.

For all I know it may just be 5 feet of clay/mud behind the bricks in the hall.

I was just hoping there would be a way of drilling using extension bars. I am really loathe to break the tiles on the pathway as they are the original victorian ones - one of the few remaing originals in the street and one of the few original features of my flat!

 

[cobweb]

In that case I'd have a look at having a bar welded onto your chosen bit and give it a go...

I think I have a clearer mental picture of what you're doing now...

In through the trench and out through the brick under the step and into the sub-floor space under the hall?

The only problem I can see is getting a horizontal angle to feed the bit and extension.

So all you'd actually need is about 5ft of bar - it would need to be substantial so that it didn't "bend" whilst underground - welded to the drill bit, and the other end of the bar grinding to fit your drill's chuck...

Try METAL WORKERS in the Thompson Local...

And let us know how you get on!

I know what you mean about the path; I have an original Victorian front path and recently had to admit defeat over replacing some missing and damaged tiles and simply infill with concrete. Still, it's better than loosing the lot.

 

[aaront]

In through the trench and out through the brick under the step and into the sub-floor space under the hall?


Exactly.

I will try your suggestion - HSS quoted £130 (I finally found someone who knew what they were talking about) to hire the drill & extension bars for the day.

 

[DAZB]

Why don't you first try to drill the required size hole through the brickwork from inside your hall and then get a suitable length and diameter steel rod and try to hammer it through to your trench as you may find you can get below any hardcore and concrete especially if you can drill down at a slight angle. It may only be soil or clay like you mention. I would advise that you keep wiggling the bar a bit and take it steady so you don't go getting it stuck but I think it would be worth a go.

 

[DAZB]

How did you get on in the end ?

 

[aaront]

Eventually gave in and dug up a section of the pathway (managed to save 90% of the original tiles so the damage isnt too bad).

Have drilled a 1.5" hole through the brickwork under the front foor sill. I still have to get either through or under the footings of the front porchway. Started to drill through and the realised it's a lot thicker than I thought. I have Transco coming on Wednesday to move the gas meter outside and I'm hoping that they'll have the know how (and maybe thr drill!) to drill this hole which is now about 500mm through brick footings & clay.

I'll let you know how I get on!

 

[masona]

When the Water Company was changing our old cast iron main water in the road to blue plastic pipe I decided to change my lead pipe water mains to blue plastic pipe from my house.I've managed to drill thru' the footing approx 250mm at a angle from the hall to outside then dug out the trench 4m long,750mm deep to the boundary line from them to connect to the new main pipe.They then told me I needn't dug out the trench as we have got a compressor mole drill which they can go anywhere they like even under the footing !! All that works for nothing ! Water Company should be able to help you out or a friendly one working nearby for beer money to help.Maybe Transo got a compressor mole drill as well for their yellow plastic pipe ?

 

[aaront]

Masona

Thats what I'm hoping for!