Garden guide
How to Point a Patio: Jointing Compound vs Mortar
The short version
Brush-in jointing compound is the easy modern option: sweep it into the joints, wet it, done. A traditional sand-and-cement mortar joint is cheaper in materials but takes more skill. Block paving is different again — it takes kiln-dried sand, no mortar at all.
Brush-in jointing compound
Sold as wet-and-set resin compound in tubs. Soak the paving, tip the compound out, sweep it diagonally into the joints, then mist with water to set it. One 15kg tub joints roughly 15m² of paving. It flexes slightly, resists weeds, and comes in greys and buffs to match the slabs.
Traditional mortar pointing
A 4:1 sharp sand to cement mix, pressed into joints with a pointing trowel and struck off smooth. Cheaper per joint and very durable done well — but it cracks if the bed beneath moves, and a messy hand stains the slab faces. Work small areas and clean as you go.
Block paving is its own world
Block and sett paving joints are filled with kiln-dried sand — bone dry so it flows into the gaps, then vibrated down with the wacker plate. It locks the blocks together while staying flexible. Top it up after every pressure wash.
When to repoint
Failed joints let in water, weeds and ants, and loose slabs follow. Rake out anything crumbly to at least 20mm deep and repoint — a weekend job that adds years to the patio. Our patio slab calculator covers replacement slabs if any have cracked.