Drilling through narrow joists for heating pipes

12 Dec 2013
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United Kingdom
I'm at the stage of drilling holes through my joists to run the 22mm flow and return pipes for my central heating.

I can only drill through the joists at angles, because I can't fit my drill in the narrow gap of joists.

My question is, will 22mm speedfit pipe be flexible enough to bend through these angles, or do I need to find an alternative way of drilling holes in my joists?

I can't think of another way, unless there's a special drill I'm unaware of.
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You can get right angle drills, although I've never had cause to need one.
The answer to your question is "depends on the angle".

Your's is not an ideal solution. You will you increase the number of bends in the pipe and you will take more out of the joists than is strictly necessary.

The best answer is a right angle drill. Second best is a right angle attachment for an existing drill. Third best is to buy one or more extra drills (assuming you are using spade bits) and cut them down so that the stub of the bit and your drill will fit the gap, then replace with the full size bit once the hole is started, or do it in stages if one change is not enough.
What's the gap between joists? I had similar issues (on another kind of job) drilling and screwing properly into joists at 400mm centres. I bought a compact 10.8V Li ion cordless drill and its a boon for getting into tight spaces etc.

Agreed, right angle drill would be even better for the job.

You may find that the first hole is awkward but subsequent ones, with a 22+mm hole right behind it, will allow the end of the case of the drill to go in that little bit, and help you out.

Also, I know its a bit dodgy but you can start drilling at an angle then as the drill bit gets further in, turn it to perpendicular with the joist you're drilling. If you're doing 22mm holes then this would be easy enough and not risk snapping a small drill bit (eg you could start with 10mm).

Or you could drill a smaller hole at an angle and use a hand file to make the hole 22mm, and square with the joists.
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you might also consider a brace and bit with a short auger.

look out for a short drill bit. A long one will just get in the way.

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