Over time, grout can become stained or dingy on tile floors, particularly in high-traffic areas. Some homeowners use grout stain or paint in deeper colours to hide stains on lighter-coloured grout. Changing the colour of your grout is also one way to give tiled walls or floors a new look without the expense of extensive remodelling.
Scrub the existing grout of all dirt and grime with grout cleaner. The colourant will not properly adhere to the grout unless it is completely clean. Allow it to dry completely.
Apply the masking tape to the edges of your tile to protect it from the grout paint or stain. This step is optional; if you have a steady hand, you can begin colouring without taping off the tiles.
Apply the grout paint or stain thinly, using the foam brush or paintbrush. Work in one small section, not more than 10 feet of tile at a time.
Allow the paint or stain to dry for the time recommended according to the manufacturer's directions. Apply a second coat if desired.
Remove the masking tape if you have used it on the tiles.
Dampen the nylon scrubbing pad and use it to remove any colourant from the tiles. If the nylon pad does not completely remove dried colourant, use a razor blade to gently scrape it off. Apply grout sealant if desired.
Grout paints or stains are available either in premixed form or as a colourant to add to powdered grout. If you are mixing it yourself, prepare enough for the entire project to ensure colour consistency.
Natural stone or clay tiles are more porous than ceramic tiles. Grout colourants may cause discolouration on these types of materials.