Handy Mac, aka Don MacAlister, is our expert on household DIY issues

SELWYN has a common problem: Q:

Please will you help me with a small problem. I want to drill into a shower wall, but I don’t know where the water pipes are located. Obviously I know where the mixer and shower head are, but that is as far as it goes. How can I find out where not to drill?

A:

This, of course, was much easier to do when plumbers still used copper pipes, there was no water shortage, and we were young enough to get into our roof voids.

Now most domestic plumbing is installed using plastic or PVC pipes. You can’t let water run for too long (you can feel hot water pipes in the wall if the water runs through them for long enough), and getting into the roof void takes weeks to plan and is seldom worth the effort.

In the days of metal pipes, a cheap metal or stud detector did the job, but the use of special plastic pipe detectors which can “see” through your walls, cost a fortune.

A quick check on the internet shows that you can buy something which attaches to your smartphone, which will give you a 3D picture of what is behind the tiles, but I don’t think any of us want to spend $200 (about R2500).

In theory, pipes run either vertically or horizontally as most bends are right-angled ones. So, the basic rule if you don’t have a fancy detector is: don’t start drilling anywhere directly above or at right angles to any taps or shower heads.

There is always a chance your taps could be fed from the bottom, but this is unusual unless the bathroom has been part of a renovation or addition.

If you can get up into the roof void to spot where the pipes are coming up out of the walls, they will more than likely go vertically down from there.

Talking about roof voids, I wonder whether any architects or designers are ever going to come up with a design for roof voids that makes them a little more user-friendly. I have always felt they are a total waste of space.

Obviously, it all comes down to cost – the lower the pitch, the less the expense, and if you wanted the trusses to carry more weight they would need to be made of heavier timber.

Some type of walkway would be such a big help.

Back to the problem at hand. Wherever possible, if unsure, use walls with no taps or shower-heads on them.

Modern technology has led to the design of many innovations for fixing bathroom accessories without screws or for hanging baskets over shower doors.

Apart from the problem of where the pipes are, there are other challenges to be overcome. Drilling through tiles themselves is no easy task. Make sure you have a special tile drill bit, and it is obviously easier to drill through the joints if they are wide enough.

Be careful with narrow joints as it is easy to nick the tiles on either side.

Finally, be sure to tap the tiles first to ensure you are not choosing a hollow spot.

There is nothing worse than drilling the perfect hole through a tile, only to find there is nothing behind for the plug or whatever fixing you are using to bond into.

Keep saving water as rainfall this month is forecast to be lower than average.

Selwyn wants to drill into a shower wall, but doesn’t know where the water pipes are. PICTURE: ABIGAIL LYNN