Drilling a hole

[John Edgar]

I have been trying to drill a hole into what appears to be breeze-block, but it may be something else, and it has not proven to be easy. When the drill is some distance in, it starts to move off centre as if something is in the way in the breeze-block, or whatever it is. I cannot stop this movement of the drill bit. What is going on here, why does this happen and what can be done to stop it? It is really quite annoying, because my beautifully marked up hole, exactly where I wanted it, becomes irrelevant, and all my hard work goes to waste.

Is there anything to be done? TIA John

[Matt]

Steel reinforcement perhaps? That would be about a 3/4 inch thick steel bar - you'd not easily get through that with a masonry bit.

You wouldn't likely get that > I have been trying to drill a hole into what appears to be

[Weatherlawyer]

Steel would do that, is it above a window or is there some iron conduit in the house? Try drilling a few inches away where you can repair the hole.

[Dave Fawthrop]

|I have been trying to drill a hole into what appears to be |breeze-block, but it may be something else, and it has not proven to be |easy. When the drill is some distance in, it starts to move off centre |as if something is in the way in the breeze-block, or whatever it is. I |cannot stop this movement of the drill bit. What is going on here, why |does this happen and what can be done to stop it? It is really quite |annoying, because my beautifully marked up hole, exactly where I wanted |it, becomes irrelevant, and all my hard work goes to waste.

Point a torch down the hole, have a scrape with a screwdriver, and see what you have hit.

[meow2222]

breeze blocks are soft enough to carve with a kitchen knife, so theyre esy to identify.

NT

[Roger]

The message from [e-mail] contains these words:

I don't think I have seen a modern breeze block but breeze blocks were traditionally made from clinker and you would need a truely remarkable knife to do more than scratch the surface of one of those.

[Andrew Gabriel]

You have to be more precise. "Breeze Blocks" is rather loosely used to refer to original breeze blocks (rather rare), clinker blocks (very common) and thermal blocks (very common). Thermal blocks behave as you describe, but breeze blocks and clinker blocks can behave as the OP described because they have lumps of all sorts of stuff in them.

[nightjar]

Some building blocks incorporate aggregate, so you could be hitting a piece of stone. It is almost certain I will if drilling the walls in one of my factory units. In that case, using a hammer drill usually works.

Colin Bignell

[Steven Briggs]

In message , Andrew Gabriel writes

Including one-pint glass orange bottles. No, really, one of the blocks in the gable wall in my loft has a whole pint bottle embedded in it.

[noelogara]

nightjar wrote: > Some building blocks incorporate aggregate, so you could be hitting a piece

thats the most likely cause and solution john. Move a few inches one side and try again but If you must drill the hole in that particular spot, try packing the small hole with a tight short wooden or plastic plug and cut down a screw to fit it. Get a few better fixings on the rest of the job. It depends on what you are fixing to the wall, a picture or a press?

[John Edgar]

Thanks for all the advice on this. At the end of the day, as it was in my garage, it was not terribly important to be accurate on this occasion and I managed to do the job even with the wandering drill bit. I think it must be pieces of stone within these blocks, whatever kind they are. I was interested to know what to do when it really matters!

Thanks again John