Hi; I am planning to tile my alfresco. currently, it has aggregate concrete.
Should i do anything to the aggregate before tiling or can i lay tiles over it?
I am planning to tile till the corner of the brickwork (please see photo)- So do i need to use a tile trim on that side? Any help appretiated. Thanks
Welcome to the Bunnings Workshop community @tkboby. It's fantastic to have you join us, and many thanks for your question about tiling over Pebblecrete.
Ardex, one of our tile adhesive manufacturers, has put great effort into investigating if Pebblecrete can be tiled over. In this document, they discuss why it isn't acceptable to apply adhesives over these finishes. ARDEX recommends the best way of dealing with Pebblecrete surfaces before applying levelling cement, ceramic tile adhesives, and membranes is to remove the Pebblecrete from the surface via mechanical methods.
The issue is that the tile adhesive will have trouble adhering to the epoxy, binders and sealer used in the Pebblecreteing process and that Pebblecrete is inherently unstable.
This doesn't mean that you can't glue tiles to the Pebblecrete; it's just that our manufacturers don't recommend it as, in their testing, it's not a suitable substrate for tiling over. If you were to attempt this, I would advise cleaning the Pebblecrete thoroughly, acid etching the surface, and then using a two-part system like Ardex Optima.
To remove the Pebblecrete, I'd advise picking up a rotary hammer drill and a wide chiselling bit. You'll also need an angle grinder to remove adhesive remnants and smooth the area. You will need to use a tile trim to protect the edge of the tiles and prevent a trip hazard.
Please let me know if you have any questions.