How do I fit a shower curtain rail that actually keeps water in?

Shower curtains get a bad name largely because of how they are hung. A rail cut exactly to the length of the bath, hung too low, with a curtain that just reaches the rim, will let water out at both ends every time. A rail that overhangs, hung higher, with a curtain tucked inside a weighted hem, keeps water in about as well as a screen and costs a fraction as much.

Safety

What you'll need

• A pipe and cable detector
• A tile drill bit and a drill with hammer action switchable off
• Wall plugs suitable for the wall behind the tile
• A spirit level and masking tape
• Sanitary silicone
• A curtain longer than the drop, with a weighted or magnetic hem

Step by step

1. Choose the rail type for the situation.A straight rail between two walls is the simplest and strongest. An L-shape or a curved rail is needed where only one end meets a wall, or where you want more elbow room over a bath. A tension rod that pressures between two walls fits without drilling and is fine for a light curtain in a rental, but it will fall down if it is leaned on and it will not carry a heavy curtain.
2. Set the height above the bath rim, not at it.Hang the rail high enough that the curtain, at its full length, hangs several centimetres below the bath rim on the inside. If the hem sits level with the rim, water runs off the curtain onto the rim and then onto the floor. Higher also means less clinging.
3. Make the rail overhang the bath at both ends.A rail that stops exactly at the ends of the bath leaves the curtain with nothing to wrap around at the corners, and that is where water escapes. A little overhang at each end, so the curtain can be pulled past the corner, makes the difference.
4. Detect before you mark.Run a detector across the whole area. Shower supply pipes rise in the wall behind, and a wall light or a shaver socket may have a cable dropping down. Move the rail rather than the services.
5. Mark the two fixings level with each other.Hold the rail up with a level on it, mark both ends, and check with the level again before drilling. A rail out of level is obvious from across the room and drags the curtain to one end.
6. Drill tile with the hammer off.Tape over the mark, tile bit, slow speed, light pressure, no hammer, at right angles to the wall. Stop as soon as you are through the tile, then switch to a masonry bit for the wall behind — and only turn hammer action on if the wall behind is genuinely masonry.
7. Fix into something solid, and bed it.The plug must be in solid material behind the tile, not in the adhesive bed. On plasterboard, use a fixing rated for board and accept a lighter curtain. Put a smear of silicone in the hole and behind the bracket so water cannot track down the fixing.
8. Hang a curtain that is long enough and weighted.A curtain that is too short is the commonest cause of a wet floor. Buy long, and either use a weighted hem or add curtain weights, or a magnetic hem that grips a steel bath. The weight stops the curtain from billowing inwards and from lifting at the bottom.
9. Use a liner, or a curtain that hangs inside.The curtain — or the liner if you use two layers — hangs inside the bath. Every time. Half of all shower curtain problems are somebody letting the hem hang outside the bath.
10. Deal with clinging.Curtains cling because the shower's spray drags air with it and drops the pressure inside. A weighted hem is the main answer; a slightly larger enclosure of curtain and a lower flow head help; and a curved rail that pushes the curtain further out solves it most completely.

Tips

• Wash the curtain or liner rather than replacing it. Most machine wash with towels at a low temperature and come out clean, and the mould in the folds is the reason people bin them.
• Shake the curtain out and leave it spread across the rail after use, not bunched. A bunched curtain never dries and it is where the mould lives.
• If a tension rod keeps falling, it is usually being loaded sideways by someone pulling the curtain. A fixed rail is the answer, not a tighter rod.

Common mistakes

• Fitting the rail level with the top of the bath tiles for neatness — It sets the curtain hem at or above the rim and guarantees water on the floor.
• Buying a rail cut exactly to the length of the bath — The curtain has nothing to wrap around at the corners, which is exactly where the water gets out.
• Fixing into a grout line — Grout is weak, the fixing pulls out under the sideways load of someone pulling the curtain, and water gets into the adhesive bed through the split.