A customer in Leyland near Preston reported a grouting issue with their porcelain tiled kitchen floor, the tiles were fine but the grout had become discoloured and grey, they were also finding it difficult to keep clean. This is not an unusual story for Porcelain or Ceramic tiled floors which are generally very low maintenance and you find the grout needs attention before the tiles do.
Applying Grout Colourant
On arrival I set up my equipment and cleaned the floor to make sure all the grout joints were free from any dirt etc., I then did a colour test on a less obvious part of the floor with the grout colour. I wanted to make sure the colourant would take to the grout and also to make sure the customer was happy with her colour choice.
The process for grout colouring is fairly tedious but straightforward, it involves giving the bottle a good shake and applying a small amount to a toothbrush and working the grout colorant into joints using a back-and-forth motion. I find the best way to apply it is by working in small areas and adding thin even coats to limit the amount of grout colorant that gets on the tile. They were large format tiles covering 9m2 so I only needed one bottle of buff grout colourant to do the entire floor.
After the Grout Colorant dries (it takes between twenty and sixty minutes depending on how warm the house) you mist the surface with water and let stand for five minutes, excess grout colorant is then removed from the tile surface using a white nylon scrub pad.
The floor was ready for surface traffic in 2 hours but there was a white mist over the floor which you can get with porcelain tiles so I fitted a white buffing pad to my rotary floor polishing machine and buffed the floor to remove the power and water marks, once finished the floor looked like new. Before leaving I left the customer with some after care instructions and how to keep it floor looking good for the future.
Source: Making Grout look new again in Lancashire