Andy Hide wrote:

1) What size plastic pipe should I use to sleeve the 15mm and 22mm
copper pipe ? Can you get special pipe sleeves for the job ?

Firstly does it need to be a plastic pipe sleeve? Or would Denso tape do
the trick? (Would need to be a propper sleeve for a gas pipe, but for
water just protecting the pipe from corrosion is enough. You could also
get away with unsleeved plastic barrier pipe for water if you wanted.

2) All I have at the moment is a 570W B&D Hammer drill. Is it worth
investing in a cheap SDS drill (e.g. £30 Ferm model in Screwfix) or

Yes. Even a cheap one will give you a hole much quicker than you though
possible before.

hiring a decent one? Can you get anything decent for around the £100
mark as it's likely to be used for other jobs in the future but I
don't want to spend £500.

A top end drill like the Makita H2450 is typically under 120 quid and
well worth it...

http://www.lawson-his.co.uk/scripts/...hisel%20Drills

3) What size bit would I need for above holes ? Previous posts
indicate you usually end up with a bigger hole than the bit you use
for the job. Do I need a core drill bit or just a standard drill bit ?

You can get 15mm copper through a hole drilled with a 16mm SDS bit. A
25mm bit will do it for 22mm. If you want another sleeving pipe then you
will need correspondingly bigger holes.

Once you get to holes larger than about 25mm, you can get larger SDS
bits, but they start getting harder to find and more expensive. You may
find a core drill a cheaper option. If you are going to use a core drill
then get a SDS with at least 700W, and make sure it has a safety clutch
because core bits tend to snag from time to time. With the safety clutch
this is no more dramatic than reaching the torque limiter on a cordless
drill when putting in a screw. Without it you may find yourself flying
off a ladder or with a clearly defined outline of a drill handle on your
right gonad!

Many of the sub 30 quid SDS units omit the safety clutch. Having a good
speed controller is also worth having especially when using the drill
for chiselling (chisel mode is not present on all drills, so check for
this)

4) Previous posts indicate drilling a small pilot hole first and then
going in half way from both sides. Any improvement on this method ?

Not necessary - even a 25mm diameter 400mm long SDS bit will romp
through brickwork etc without any problem.

--
Cheers,

John.

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