Every patio job starts with a site assessment: the area is measured, the existing ground level is checked, and how water currently moves across the garden is noted. On Cambridgeshire clay, this step matters more than it does on free-draining soil. The clay shrinks and swells with the seasons, so the sub-base depth is set to suit the specific ground conditions rather than a standard figure. Once the assessment is done, excavation removes the existing surface and topsoil down to a stable layer. A compacted Type 1 hardcore sub-base is then built up in layers, each one compacted before the next goes down. The finished level is checked against the damp-proof course to make sure the new patio surface sits below it.
With the sub-base in place, the bedding layer is prepared to suit the chosen slab. Porcelain on a full mortar bed needs a priming slurry applied to the back of each slab before it is set; Indian sandstone and limestone sit on a sharp sand and cement mix, with the bedding depth adjusted for the slab thickness. Drainage falls are set during this stage, a minimum 1:80 gradient away from the house, and ACO channel drains are positioned where the garden layout means surface water cannot run clear of the paved area. Slabs are then laid to the planned pattern, cut to fit at the edges, and checked for level and alignment before the mortar sets.
The final stage is jointing and finishing. The jointing compound is chosen to match the slab type: a brush-in polymeric jointing sand for block and some natural stones, a mortar-based compound for porcelain and denser natural stone. Once the joints are filled and cured, the installer carries out a drainage check, running water across the surface to confirm falls are working as specified. Edge restraints, step nosings or retaining edging are mortared in as the last structural element. The result is a surface that is ready to use, drains correctly, and does not need the joints or bedding revisited within the first couple of seasons.