Few things take the shine off a Saturday morning faster than the sound of a tile cracking under a masonry bit. The drill is rarely the problem. The bit, the speed and the amount of hammer you're using are almost always what decides whether you get a clean hole or a repair job. Each wall material wants something different from you, and once you know what that is, drilling stops being a gamble.

Match the bit to the material first

Half of all cracked tiles and blown plaster come down to using whatever bit was already in the chuck. Sort the bit out before anything else.

• Masonry bit (tungsten carbide tip) — brick, block, mortar, stone, render, and the solid wall behind a tile. Cheap ones are fine for a handful of holes; they blunt quickly and a blunt bit is a hot bit.
• SDS-Plus bit — the same cutting job, but for a hammer drill with an SDS chuck. Much faster in brick and concrete, and worth borrowing if you're drilling more than a few holes.
• Tile bit — either a carbide spear-point or a diamond-grit bit. Spear-points are fine for a couple of ceramic tiles; diamond grit copes far better with porcelain.
• HSS twist bit — plasterboard, timber, metal. A brad-point bit leaves a noticeably cleaner hole in plasterboard.
• Multi-purpose bit — useful for a one-off hole through tile and brick together, but they wander and dull quickly.

A blunt bit doesn't cut, it rubs. Rubbing generates heat, heat glazes the cutting edge, and the extra pressure you then apply is what cracks tiles and blows plaster off the wall. If the tip is blackened or rounded, replace it.

Brick and block: hammer on, heat down

For ordinary red brick, blockwork and mortar, use hammer action. Start the hole at a slow speed with light pressure so the bit bites instead of skating across the face, then build up to a moderate, steady push. Most corded hammer drills have two gears; low gear with the hammer on is almost always the right setting for masonry.

Don't lean on the drill and don't hold the trigger down continuously. Pull the bit out every few seconds to let the dust clear — the flutes can't cut when they're packed solid. If the bit stops making progress and the shank starts to feel warm, stop and let it cool.

Hard engineering brick is a different animal. It will blunt a cheap masonry bit in seconds, so start with a 5.5mm bit and open the hole up to the size you need in stages. Keep away from brick edges and corners, which split easily, and remember that mortar joints are easy to drill but hold a fixing poorly — fine for a light cable clip, not for a shelf.

Tiles: hammer off, always

Hammer action through a tile is the single most reliable way to blow it. Switch it off and slow the drill right down.

Stick a square of masking tape over the spot to stop the bit wandering and scratching the glaze. Start the bit at roughly 30 degrees to the surface, drill a small nick to break through the glaze, then bring the drill upright and continue. Use light pressure and let the bit cut.

Heat is the enemy here. Diamond bits and porcelain do not get on well when they're hot, so pause often. A ring of plumber's putty or a lump of sticky tack around the hole, filled with a little water, will keep the tip cool.

Two more things. Keep holes at least 25mm from tile edges and corners if you possibly can — that's where cracks start. And once you're through the tile, stop: the wall behind might be brick, block or plasterboard, and each wants a different bit and setting. Tape a folded paper envelope below the hole to catch the dust; it saves a lot of cleaning on a finished bathroom wall.

Plasterboard: sharp bit, light touch

Plasterboard needs no hammer action at all. Use a sharp HSS or brad-point bit at a moderate speed with almost no pressure — the weight of the drill is usually enough. Push too hard and the bit grabs and tears the paper facing, which weakens the fixing.

When you're drilling through plasterboard to reach the wall behind, ease off as the bit breaks through, otherwise it lunges forward and bursts the rear paper face.

Also accept that plasterboard alone holds very little. A standard wall plug will pull straight out. Choose the fixing to match the load:

• Light items up to a couple of kilos: a metal self-drill plasterboard fixing.
• Mirrors, shelves and small cabinets: a spring toggle or a proper hollow-wall anchor.
• Anything heavier, or anything that gets pulled about: find the studs or fix into the solid wall behind.

Old plaster, lath and render: slow and sharp

Old lime plaster and lath crumbles if you look at it wrongly, and hammer action will take a chunk off the wall. Use a sharp bit, low speed, no hammer, and masking tape over the spot to stop the drill skating. Start at 4mm and widen gradually rather than going in at full size.

Tap the wall first. If it sounds hollow, the plaster has already separated from the backing and a drill will push it off. Either drill in a solid-sounding area, or accept that you'll be patching afterwards.

Behind lath and plaster is a timber framework with voids between the slats, so a plug has nothing to grip. Fix into the studs, or use a toggle that opens behind the lath. Don't be surprised when the drill drops through the plaster and there's suddenly nothing to push against — that's the void, not a mistake.

Before you pull the trigger

1. Check for hidden cables and pipes with a detector. Avoid the zones directly above, below and level with sockets and switches, and remember pipes often run up walls in older properties.
2. Mark the hole with a cross, then centre-punch it or make a small dent with a nail so the bit starts true.
3. Wrap a strip of tape around the bit to mark the depth you need. Drill about 5mm deeper than the plug.
4. Tape the surface for tiles and old plaster, and have goggles and a dust mask on. Keep a vacuum or dust sheet handy.
5. Have a spare bit of each type to hand so you're not tempted to make the wrong one do the job.

When to stop and call someone

Some jobs deserve more caution than a YouTube clip suggests. In homes built or refurbished before about 2000, textured ceiling coatings, some ceiling tiles and older insulation boards can contain asbestos. If you're unsure, don't drill — get it identified by a qualified professional first. The same applies if you hit unexpected resistance, metal or something that might be a cable or pipe: stop, and get an electrician or plumber to look.

Beyond that, the rules are simple. Right bit, right speed, hammer on only for masonry, light pressure, and clear the dust often. Do that and you'll finish the job with a neat row of holes and a wall that looks exactly as it did before you started.

Photo: Christina & Peter / Pexels