Drilling a hole through a house wall

You can get drill bits that long. Got mine in one of the sheds many moons ago.

OK, thanks for the info. Am I likely to succeed in getting through, with a standard hammer drill? I'm thinking 8mm should be enough ...

yes..for all but engineering brick. But pull it out and clear the muck periodically.

a hammer drill should go through ordinary brick and block.

You probably will, but it may make a simple 1 minute job into a lot of hassle. I wouldnt try drilling 2 holes from both sides, its a recipe for failure.

NT

Depnds on the bricks, standard soft red things no problem, engineering bricks you will wish you had your SDS drill...

Strkes me as a bit tight even for 1mm T&E.

It's a recipe for 2 holes :-)

I did 10mm or 12mm, standard hammer drill (Bosch green).

How best to fill the hole afterwards?

I'm putting though some white plastic cable channel, putting the cable inside that, then filling in with foam, then scraping away the foam at the outside and putting in cement.

The hole should slope towards the outside so any water goes outwards.

You can, although you might need to go to a 10mm hole

No.

through a 34cm brick wall,

whatever for?

NT

Do you have cavity wall insulation? If so take care when breaking through the cavity, as the bit will be hot and the insulation may melt and stick to it. Best to let the drill bit cool down for a while before proceeding to drill through the next layer.

My sons house still has an SDS bit sticking out of the wall from when I drilled for a 15mm water pipe for an outside tap. The bit got jammed solid and wouldn't go in further, or come out. Fortunately it's now behind a cupboard!

through a 34cm brick wall,

to avoid water going inside when it rains.

I'd have thought that it would be at least worth trying to match interior and exterior locations by careful measurement from a nearby door, window or whatever, and then drilling in just over half the thickness from first one side then the other.

If the two holes meet, great; if they don't, then the worst that can happen is that you have to carry on with one of the two holes and block up the other.

Bert

and where the cable exits the hole it should go downwards first to avoid rain running down the cable into the hole.

And for completeness satisfy yourself there are no cables or pipes where you intend to drill (says he who put a screw through a central heating pipe last year screwing down creaking floorboards).

I think he means "so that any water trickling down the outside wall will not run into the hole and thence to the interior of the house".

I'm going to put up one of Ikea's excellent little outside lights, and this seems to have a pretty good seal on the wall. (I just put one up, using the wire-through-wall of a real electrician.) But I will make the hole run slightly downwards, as that sounds sensible. And I'll try for 10mm rather than 8mm.

I regard that as a matter of luck (good or bad). I bought a Lidl device some time ago which was meant to tell you where the wires were in the wall, but it never seemed to tell me anything.

I actually drilled through a water pipe under a floor-board a couple of years ago, and was amazed how much water came through a tiny hole. I managed to convince myself that it was the fault of the plumber (a friend of mine) for putting the pipe in such a silly place. I think he was quite pleased to see, as he cleared the mess up, what damage an amateur plumber can do.

Fortunately I saw a little dampness round the head of the screw. I drained the system before removing the screw and lifting the board and was amazed how little water had escaped.