Question From Sandy from Sydney

Dear Brett,

I mostly do my mosaics by attaching the tiles directly to sandstone then grouting.

I thought i could improve the finish of my pieces by putting a rebate into the sandstone and glueing the tiles into the rebate, thus having the tiles flush with the surface of the sandstone.

I have never used power tools and have no idea how this rebate could be achieved and wonder if you have ever done it yourself, and if so, what tool did you use? Any ideas would be appreciated.

Sandra.

Reply from Brett

Hi Sandra

The works here were done exactly the way you described.

I cut some pieces of compressed fibre cement in the shape I wanted, and then traced the outline onto the sandstone. I then allowed about 5mm around the outside of that and drew in the areas to be cut. The reason I went with fibre cement is that I felt the surface of the mosaic should be perfectly flat & I wanted to lay them direct in the studio – the site was a 2 hour drive – I wanted installation to be simple.

I was cutting to about 20mm( to allowed for the compressed sheet thickness., but if you’re going to tile straight into the rebate, I’d be inclined to go 10-12 mm. You then have to sit there patiently and grind out the rebates with a grinder fitted with a diamond blade (turbo style). You can probably get more aggressive diamond wheels, but I was happy enough to go with it this way.

If you’re doing a large area, you could cut into the stone in a criss-cross, and knock the chunks out with a chisel.

The hardest part is getting a consistent depth, but you’ve got a fair amount of tolerance when you’re working with cement glues – just go too deep rather than too thin, and use a bit more glue.

Hope that makes sense & is helpful.

Cheers

Brett