Mosaic Workshop — Student Resources
Easy Mosaic Grouting Guide
A simple guide to finishing your mosaic at home
⚠️ Before you start
Wear gloves and a mask when grouting, and work in a well-ventilated area.
Step 1 — Mix the grout
Put grout powder into a container and add a little water at a time. Mix until smooth and thick, like thick yoghurt. Don't make it too runny.
Step 2 — Cover the mosaic
Spread grout over the mosaic, pushing it firmly into all the gaps. A small sponge can be useful for pressing grout into awkward gaps. Be sure to cover the sides and edges too, so the finished piece looks neat. It's fine to cover the tiles completely.
Step 3 — Remove the excess
Use a rubber squeegee, old bank card or gloved finger to scrape excess grout from the surface. Leave the gaps filled.
Step 4 — Let it firm up
Leave for around 10–15 minutes so the grout begins to firm up. You'll know it's ready for a wipe when the grout starts to "dust up" slightly on the surface.
Step 5 — Clean with a damp sponge
Use a well-squeezed damp sponge to gently wipe the surface. Rinse often. Use light passes so you don't pull grout out of the gaps.
Step 6 — Polish
Once the surface has dried further, use a soft, dry cloth to gently polish away any remaining grout haze.
Step 7 — Leave to cure
Leave your mosaic undisturbed for at least 24 hours. The grout will continue to harden over the following days.
💡 Top Tips
- Add water slowly — you can always add more.
- Don't use too much water when cleaning; excess water can weaken or wash out the grout.
- If a little grout haze remains, allow it to dry further and polish gently with a soft cloth.
- If you want to varnish your mosaic, allow the grout to cure for 2 weeks before applying varnish.
🚫 DON'T POUR LEFTOVER GROUT OR GROUT WATER DOWN THE SINK — UNLESS YOU WANT A COSTLY PLUMBING BILL!
Remember: Fill the gaps, cover the edges, remove the excess, then clean gently. Take your time!