Driveway resurfacing & overlays

Resurfacing is the best value job in this trade when it is the right job, and a waste of money when it is not. The distinction is simple to state and takes a bit of work to establish: a new surface adds appearance and weather resistance, and adds essentially nothing structurally. So if the layers underneath are stable, an overlay is excellent. If they are moving, the overlay moves with them.

What makes a base suitable is that it is solid underfoot, well drained, at a level that leaves room for the new surface, and free of the kind of cracking that indicates movement below. Old concrete is often ideal — it was built heavy, it has usually stopped moving decades ago, and it makes a first-class base for resin bound. Sound but tired tarmac is the other common candidate. Both get walked, sounded and, where there is any doubt, opened up in one place to see what is under them.

The disqualifiers are worth knowing because they are the ones people argue with. Cracks with a step across them, or that have opened wider over time, mean something is still moving. Areas that rock or sound hollow mean voids underneath. Standing water means the drainage was never right and covering it will not make it right. And a base that is already at the level of the damp proof course or the garage threshold leaves nowhere to put a new surface without creating a water problem at the house.

The three usual overlay systems all behave differently. A tarmac overlay — a wearing course laid over the prepared old surface — is quick, forgiving and cheap, but it needs a proper edge and it will reflect any live crack beneath it eventually. Resin bound at 15–18mm gives a smooth, permeable, joint-free finish and is the most transformative of the three, but it is also the least tolerant of a poor base. Resin bonded is thinner and rougher, is not permeable, and suits a slope or somewhere grip matters more than looks.

Preparation is where an honest resurfacing job spends its time. Weeds and moss killed and removed rather than covered. Oil contamination cut out, because resin will not bond to it. Cracks routed out and filled. Potholes and low spots regulated so the new surface has a consistent thickness. Edges cut back to something solid. Skip that and the new surface simply inherits every fault of the old one, on a shorter timescale.

One structural point that catches people out: an overlay raises the finished level, and everything at the edge of the drive has to still work afterwards. A garage threshold, a doorstep, a gully, an inspection cover and the kerb line all need to be checked against the new height before the material is ordered — not discovered on the day the drive turns out to be 20mm proud of the garage floor.