My newly painted bathroom vanity (here) was being let down by the icky colour of the floor grout. It needed a good scrub and repaint.
A year and a half ago I painted the grout between the floor tiles white in our bathroom with Zinsser primer/sealer/undercoat. You can see that post here.
The grout is naturally grey and some of the paint appears to have worn off in some areas so I decided it was time to give it a recoat.
Our bathroom is very small so it was not a hard job, and from previous experience the results are well worth the effort.
This time however I decided to add some fine grout to my paint (the same as making chalk paint) to hopefully make it stick a bit better. Afterall, it was grout I was covering. :)
Firstly I made a paste of baking soda and water and grabbed a padded sponge and cleaned the grout between all the tiles. Then I wiped it over with paper towels to take off the excess water. I left it a further day to fully dry out between the tiles.
I mixed half a cup of paint with a tablespoon of fine grout powder so it was a nice thick consistency. Using a small art paint brush I painted over all the grout between the tiles, wiping any excess off with a paper towel.