Drilling through Cellar Wall - Foundations?

[Jacob98]

I'm installing a new water main, the pipe must run through a 100mm duct.

The pipe will enter the property through the Cellar wall.

I'm hoping to do this using a core drill.

I've drilled a pilot pilot using a 10x1000mm sds bit, with about 200mm left over.

Am I drilling through the foundations, can I drill through here. The old pipe entered slightly higher. (Too high - not to water regs).

Will the strength of the building significantly weaken through me doing this.

The property is a three story (+ basement) terraced house built around 100 years ago.

 

[Blagard]

It sounds like you are drilling blindly into the cellar wall without having excavated a pit the other side.

You used a drill bit 1m long and had gone 800mm in when what happened ? On the way was it alll brick dust coming out as you drilled?

If the old water main is shallow due to foundations or other obstruction, have you considered replacing with the shallow section insulated. - Have a chat with your water board inspector.

As for the position of foundations, I regret my crystal ball has failed me. However, in general I would expect local foudations to be at a depth deeper than your cellar. A pit the other side of the cellar wall would be a good idea!

It is possible for some old properties to have very thick walls, so perhaps that is all it is, although I think it would be rare for a 100 year old house to have cellar walls that thick without good reason.

 

[Jacob98]

Thanks for replying, I appreciate it.

Sorry, I don't think I was clear. I drilled through with a 1m bit and it came out on the other side with about 200mm to spare. So the wall is about 800mm thick.

I think its constructed of mainly of brick and stone.

The old pipe was probably just installed to the water bylaws at the time.

Its a fairly large room in the cellar, there is at least another meter below the hole I want to drill to the floor.

If this is a foundation wall, would drilling a 100mm hole usually have any affect on the structure?

 

[TonyW2]

Could you explain more.
Is this "cellar" underground and if so how does the drill "come out the other side"?
What is the wall built on---would not that be the foundations?
In any case a 100mm round hole in a wall will not cause the building to collapse.

 

[Blagard]

Thanks for replying, I appreciate it.

Sorry, I don't think I was clear. I drilled through with a 1m bit and it came out on the other side with about 200mm to spare. So the wall is about 800mm thick.

I think its constructed of mainly of brick and stone.

The old pipe was probably just installed to the water bylaws at the time.

Its a fairly large room in the cellar, there is at least another meter below the hole I want to drill to the floor.

If this is a foundation wall, would drilling a 100mm hole usually have any affect on the structure?

I think I understand,

By foundation wall I think you mean a load bearing wall that goes down to the foundations. With no other openings in the cellar wall for things like basement windows and coal chutes to be considered it should be no structural problem at all to drill a 100mm hole through. But please note, if the wall has a rubble filling you may find part of it falling into you new horizontal hole!


I am not familiar with the tricks of the trade to overcome falling rubble (If there is any). So perhaps others who have done similar can give a tip or two.

Although you have not mentioned it I feel sure you must have dug down the other side of the wall to see the drill poke out! - That would be the pit I mentioned. If you have not dug down I suggest you do to check for any obstructions. It would not do to dill through and find that your 800mm thick wall is really a thinner wall with a manhole nearby and that you also drilled through that!

 

[Jacob98]

Job done, thanks for the advice.