Slabs become uneven when the ground or bedding material underneath settles unevenly over time — the slabs themselves are often still perfectly sound, they're just no longer sitting level or draining correctly.
This is a subtly different problem from a damaged patio. Ground settles at different rates in different spots, especially where drainage isn't even across an area, and over several years this can leave a patio or path with slabs at slightly different heights, or with a "fall" (slope) that no longer directs rainwater away from the house the way it should have originally. None of this necessarily means the slabs are cracked or broken — they're simply not sitting the way they were laid.
This is why slab relaying is a distinct job from patio or paving repairs: instead of replacing damaged material, the existing (still sound) slabs are lifted, the base underneath is corrected and properly compacted, and the same slabs are relaid level and with the right fall for drainage. This is usually more cost-effective than full replacement, since the slabs themselves don't need to be new — just properly re-based.
A common sign it's needed: water pooling on a patio or path well after rain has stopped, rather than draining away within a reasonable time. This is a common job across Preston and Lancashire gardens, especially on patios and paths laid more than five or so years ago.
GreenFix provides slab relaying across Preston and Lancashire. From £95 (guide price only, confirmed after assessment).
