We have some nice looking steps to our door built last year with brick risers and Bradstone concrete slab treads. The treads are bedded on mortar but are nonetheless loose. I have no idea how the builders achieved this, but we have already made them try to remedy the situation, to no lasting effect.
Has anyone got ideas of why they haven't stuck and what I could possibly do about it?
Leo
Maybe not enough suction from the mortar when they laid them. You could probably re-bed them with Gripfil (the original solvent based version, aka gorilla snot)
almost certainly they were trodden on before they set, or the mortar was so weak its broken down.
and what I could
Lift the slabs smash up the mortar and remove, and reset in STRONG mortar (2:1 sand:cement).
wrong mix, dirty surface, too dry ... ?
give underside of slab good clean with wire brush .. prime with Unibond solution, bed onto a good 4:1 mix. As you want good adhesion I would use a bricklaying mortar consistency rather than semi-dry.
Have something to add? Share your thoughts — no account required.
Ask the community — no account required