Outdoor Tiling on old slab

[OBBob]

Hi All

I have searched but can't find a guid to doing this.

I need to tile an old external slab. It is in about four sections (expeansion gaps, whatever they are). Can I just clean this and use some sort of adhesive direct onto it, or do I need to fix sheeting first, or lay a base of cement and chickenwhire first?

Can someone point me in the right direction?

[Dirty Doogie]

If the surface of the slab is very smooth trowelled you'll have to get rid of the lattiance in the surface - wire brushing and/or etching with acid works a treat. If the surface is roughish and weathered a good dose of bleach/chlorine and a bit of a scrub is all it needs. Use a tile glue suitable for exterior situations and leave a grout line over or very near the expansion jiont. Fill that groutline with polyurethane if you can.