Hello,
I am replacing old quarry tiles (about thirty) on on the risers of a small set of concrete garden steps. I've taken off the old tiles and have patched cracks and water/frost damage etc, with mortar.
Can anyone recommend a strong water proof adhesive for this situation - only need enough for thirty 6x6 inch tiles?
Also would like to finish the job with a grey outdoor grout from a tube using applicator gun - can anyone recommend this product as well?
Much obliged for any help....

it depends on what you can get locally, a powdered flexible adhesive is a must.

yes a single part flexible powder adhesive and you must ensure you get a solid bed fixing, you will need to back butter the tiles as well as spreading the adhesive on the risers! I would use a flexible grout too! but dont know of one that is specific for an applicator gun. never used one before.
Just ask at your suppliers and specify it is for exterior use....

OK - thanks both for your advice....