Driveway trip hazards & uneven paving

Of everything on a driveway, this is the fault worth acting on promptly, and for a reason that has nothing to do with the drive itself. A raised edge of ten or fifteen millimetres is enough to catch a toe, and it catches it worst in the dark, in the rain, and for the people least able to absorb a fall. If there is anybody elderly or unsteady coming to your door — and there is: the postman, a delivery driver, a visitor — an uneven surface stops being a cosmetic issue.

The commonest causes are all fixable. A slab or block that has been lifted by a tree root, usually one running under the drive from a tree in the verge or the neighbouring garden. A block that has dropped into a settled trench, leaving its neighbour standing proud. A paving flag laid on mortar dabs rather than a full bed, which has rocked, cracked and tipped. Frost heave lifting a corner. Or an edge course that has been driven over and pushed out, leaving a step where it meets the surface.

Making it safe is quick and usually the same visit. The offending unit is lifted, the bedding beneath is corrected, and it goes back level with its neighbours. Where a root is the cause the choice is between cutting the root — which is not always acceptable, and never on a protected tree — relaying with a detail that accommodates the movement, or rerouting the paving around it. Where a bay has settled, that bay comes up, the base is filled and compacted, and the units go back.

The wider question is whether the same thing is happening elsewhere on the drive, and that is worth a proper look rather than a glance. One lifted unit over a root usually means more roots and more units in the same line. One rocking flag on dabs almost always means the whole area was laid on dabs. One dropped block by a chamber often means the chamber surround is failing, and there will be more.

There is also a liability dimension it is fair to mention without overstating. As an occupier you owe a duty of care to lawful visitors under the Occupiers' Liability Act 1957 — to take such care as is reasonable to see that they are reasonably safe. A known trip hazard on a drive you use every day is exactly the kind of thing that duty is about. That is a reason to sort it, not a reason to panic, and it is worth photographing the repair when it is done.

As an interim measure, and only as an interim one: mark it. A bright cone, a plant pot, a length of tape or simply moving where people walk is better than nothing while a repair is booked in. What does not work is a bag of ready-mix feathered over the lip, which cracks off within weeks and leaves loose material as well as a step.