Grouting uneven mosaic art surfaces

Grouting can be tricky at the best of times, but it's even harder when you have glass of varying heights. 

To avoid an uneven mosaic surface, the first thing you can do is to choose a range of mosaic glass that is the same height. For example, you could choose all glass that is 3mm high. This is important if you are creating a functional mosaic such as a tabletop or coaster. If you can't avoid using different heights of glass in a functional mosaic piece, one solution is to pour a layer of clear resin over the surface, or place a sheet of glass over the top. 

If however, you want to use a range of glass tiles that are at different heights and you don't need the glass surface to be flat, there is a way to grout uneven mosaic art.  

How to grout uneven mosaic art

1. Start by mixing your grout to a smooth, toothpaste consistency. A rough guide to follow is 150ml of water to 500g of superfine grout. 

It is important that you avoid grout that is too wet as it will sink and crack. The thicker and drier the grout, the higher it will sit up towards the top of your glass. Again, toothpaste consistency is best. You can achieve this by adding your water a little bit at a time, a bit like making icing. 

2. When you are satisfied with your consistency, apply your grout with a squeegee. We recommend this one that has more flexibility and will allow you to work most of the grout where you want it. 

3. Take a look and see where the grout is sitting high against the glass. You can then use a small, thin, dampened paintbrush or your finger to sweep the grout and settle it further down into the mosaic for an even finish. Gentle pressure will help the grout settle into the gaps between the glass so you are left with an even level of grout across your mosaic.

4. Once you are happy with your grouting, smooth over the surface with a damp sponge and allow to dry.