Clean grout thoroughly, then apply a grout pen or recolouring paint to restore crisp white or coloured lines between tiles.
GR-01Clear the area and protect surfacesMove bath mats, bins and any loose items out of the way. Lay an old towel or dust sheet on the floor to catch drips. If you're working near a shower tray or bath, cover the plughole with tape so debris doesn't wash down it.
GR-02Open a window or turn on the extractorGrout cleaners and recolouring products can have strong fumes, especially bleach-based ones. Open a window and, if you have one, switch on the extractor fan. Keep the door open too if the room is small.
GR-03Scrub the grout lines cleanUse a grout brush or an old toothbrush with a grout cleaner or a mix of warm water and bicarbonate of soda. Scrub each line firmly, working in small sections. Rinse with clean water and a sponge as you go.
GR-04Treat any black mould or mildewIf you see black spots, apply a dedicated mould remover and leave it for the time stated on the bottle, usually 10-15 minutes. Scrub again, then rinse well. Wear rubber gloves for this step, as most mould removers contain bleach.
GR-05Rinse thoroughly and let it dry fullyWipe down all tiles and grout lines with clean water to remove any cleaning product residue. Leave the area to dry completely for at least a few hours, or overnight if possible. Grout pens and paints won't bond properly to damp grout.
GR-06Choose a grout pen or a recolouring paintA grout pen is a marker-style tool, quick to use and best for narrow lines and small areas like a splashback. A grout recolouring paint comes with a small brush and covers wider or more worn grout better, and usually lasts longer. Pick a shade close to the original, or go for white for a fresh look.
GR-07Mask off the tile edges if you want crisp linesFor a really neat finish, especially with paint, run masking tape along each side of the grout line before you start. This stops the product bleeding onto the tile face. Skip this step if you're using a fine-tip grout pen, as it's usually accurate enough on its own.
GR-08Apply the product along the grout linesWork in short sections, following the grout line with steady, even pressure. With a pen, go over each line once or twice until it's solidly covered. With paint, use the small brush to work it into the grout, then wipe any excess off the tile immediately with a damp cloth before it dries.
GR-09Remove the masking tape while the product is still wetPeel off the tape slowly, pulling it back on itself rather than straight up. This gives the sharpest line. If you left it too long and it's dried, a sharp craft knife will trim any ragged edges once fully cured.
GR-10Let it cure before getting it wetCheck the product's instructions, but most grout pens and paints need 4-24 hours to cure fully. Keep the shower or bath dry during this time. Avoid cleaning the area with harsh chemicals for the first week to let it settle properly.
GR-11Tidy upRinse brushes and sponges, wipe down surfaces, and put your dust sheet or towel in the wash. Store any leftover grout pen or paint with the lid tightly sealed so it doesn't dry out before your next job.
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