In article ,
Stephen wrote:
I tried to drill a hole through a 500mm concrete wall yesterday. I was
hoping to put a 15mm copper pipe through to an outdoor tap (you may
remember my other thread about the old pipe freezing and bursting).

I was unsuccessful. I used an sds drill and I got through the wall
quick enough but although I (thought I) held the drill level, the exit
hole and the entry hole were at two different heights and passing a
pipe through was impossible.

Now that I know from the "one metre drill bits at Aldi" thread that
these bits are flexible, is it possible that the bit deflected inside
the wall?

Don't think they're *that* flexible. Did you try drilling through again
from the other side? And moving the drill in slowly? Concrete has 'stones'
in it which can deflect the cutting part of the drill enough to cause a
less than perfect hole.

I'd tend to use a drill quite a bit larger than the pipe and sleeve it
with PVC where it passes through the wall - you can get clip on sleeves
designed to pretty up radiator tails which work fine.

--
*Sticks and stones may break my bones but whips and chains excite me*

Dave Plowman London SW
To e-mail, change noise into sound.