The "Overlay" Con: Why Pouring Resin Over Old Concrete is a Ticking Time Bomb
Thinking of laying a resin driveway over old tarmac? Discover why the "overlay" method causes reflective cracking and why full excavation is the only permanent fix.
You get a knock at the door. A bloke in a van says he can lay a brand-new resin driveway for half the price of the other quotes.
His trick? He isn't going to dig anything up. He tells you your old, cracked concrete or tarmac is the perfect "solid base." He mixes up some resin, trowels it straight over the top of the old drive, takes your money, and disappears.
It looks brilliant. For about four weeks. Then the ground shifts, and the whole thing tears itself to pieces.
The Reflective Crack
Let me explain why your old driveway cracked in the first place. The ground underneath it failed. The sub-base sunk, the concrete lost its support, and it snapped under the weight of your car.
Pouring a thin layer of resin bound over that old concrete does not fix the sinking ground.
When winter hits, that old concrete shifts again. The crack opens up. Because the new resin is stuck directly to the concrete base, the movement rips the resin apart right along the exact same line. In the trade, we call it reflective cracking. You've just paid thousands to put a shiny plaster over a broken foundation.
The Drainage Trap
It gets worse. Proper resin bound driveways are designed to be fully porous. Rainwater is supposed to pass straight through the stone and drain safely into the earth.
Old concrete is not porous. If a cowboy lays a resin driveway over tarmac or concrete without drilling massive drainage holes, the water passes through the resin and hits a solid wall. It has nowhere to go. It pools up inside the resin layer.
When January brings a hard frost across Dorset, that trapped water freezes solid. The ice expands and literally blows the resin off the concrete base. You end up with massive bald patches where the stone has crumbled away to nothing.
The Proper Dig Out
We refuse to do overlays. If you want a resin drive that survives the winter, you have to do proper resin groundworks.
We bring the heavy diggers in. We execute a full driveway excavation right down to the dirt across your Bournemouth or Poole property. We compact a heavy-duty MOT Type 1 sub-base to stabilize the ground permanently. Then we lay a fresh, open-graded porous tarmac binder course. Only then does the actual resin go down.
The ground doesn't sink. The water drains straight through. The driveway doesn't crack.
Stop falling for the cheap overlay con. Do it right from the dirt up.
Don't just take my word for it. Pop down and see our showcase at Dobbies Garden Centre, 24 Wareham Rd, Owermoigne, Dorchester, DT2 8BY. Walk on the stone yourself and see what a proper foundation feels like.
