How to fill gaps between concrete pavers on stairs?

BettySue

I’m gluing down concrete pavers on top of stair treads built into the retaining wall, which have been core filled with concrete. Planning to glue them down with liquid nails landscape. There will be pavers either side of the stairs that will be laid on a bed of sand and gaps filled with appropriate sand filler.

what can I use to fill in the gaps between the pavers on the stairs? I was thinking a mortar or glue, but want something that is mould resistant as this area doesn’t get much sun in winter.

MitchellMc

Hi @BettySue,

I think the first question is whether the gaps need to be filled at all. Since you’re laying the pavers over a solid, core-filled base, you could butt them up closely and adhere them in place, similar to how capping is installed on retaining walls.

As the pavers have flat, finished edges, you can apply a thin bead of adhesive (just enough to bond without forcing them apart) and bring them together neatly. This will likely give you the cleanest overall finish.

If you do want to leave a gap and fill it, a mortar would be the way to go. Once it’s cured, sealing it with something like https://www.bunnings.com.au/betta-tilecare-1l-stone-concrete-sealer_p0612134 can help reduce water ingress and minimise mould or algae build-up, especially in a shaded area like yours.

Please let me know if you have any questions.

Mitchell