Safety issue — dealt with promptly
Sunken & subsiding driveways
In short
A driveway that has dropped in one area has lost support underneath it, and the reason matters — a settled service trench is routine, a void over a failing drain is not. The area is opened up and the cause established before anything is relaid, and a sudden or deepening hollow gets looked at quickly.
Also called: Driveway sinking · Dip in my drive · Driveway subsidence · Drive collapsing over a drain
Signs you need this
- A dip or hollow that holds water in one part of the drive
- A neat rectangular depression, usually across an old trench line
- A hollow that is visibly getting deeper over months
- The surface sounding hollow or drummy when you walk on it
- Settlement directly over or beside a manhole or inspection chamber
- Cracking radiating out from a low point, or blocks tipping into it
Driveways do not sink because the surface got heavier. They sink because something beneath them lost volume — and there are only a handful of things that do that. A trench backfilled loosely years ago finally consolidating. A sub-base that was never compacted properly, or was compacted in one thick lift instead of layers. Fine material washing out of the base into soft subgrade. A tree root that has died and rotted away. Or, the one that matters most, a cracked or collapsed drain washing soil out from under the drive into the sewer.
That last cause is the reason a sunken drive is worth looking at rather than living with. A leaking drain does not settle to a new level and stop; it keeps taking material away, and the hollow above it keeps deepening until the surface bridges a void and then gives way. If the dip is over a known drain run, has appeared quickly, or is getting visibly worse, that is the first thing to rule out — and it is ruled out with a camera survey rather than an opinion.
Most sunken drives are far more mundane. A neat rectangular depression across the drive is almost always an old service trench — water, gas or electricity — that was backfilled with the spoil that came out rather than with compacted stone, and has taken a few years to settle. Those are stable once they have finished consolidating, and they simply need lifting, filling with proper compacted stone and relaying.
The repair follows the diagnosis. The affected area comes up, the void is excavated back to firm ground, and clean crushed stone goes in and is compacted in layers. Where the cause was drainage, the drain is repaired or lined first, because relaying over a live leak is pointless. Where the subgrade is soft, a geotextile membrane and a thicker stone layer spread the load rather than letting the same thing happen again. Then the surface goes back.
Block paving is the surface that copes with this best by a long way — it lifts, the ground gets sorted, and the same blocks go back with no visible sign anything happened. Tarmac and resin repair visibly. Imprinted concrete cannot be repaired to match at all, so a settled area on an imprinted drive is a genuinely awkward problem and worth knowing about before choosing that surface.
There is one situation here that does deserve treating as urgent, and it is worth being precise rather than dramatic about it. If a hollow has appeared suddenly, is deepening week by week, sounds hollow when you walk on it, or sits directly over a manhole or a drain run, do not park on it and do not let anyone stand on it. That pattern is consistent with a void, and a void gives way all at once. Everything else on this page can wait for a dry week.
What the job covers
- The cause established before anything is relaid
- Drain camera survey where a defective drain is a realistic cause
- The area lifted and excavated back to firm ground
- Voids filled and the base rebuilt in compacted layers
- Geotextile membrane and a thicker build-up over soft subgrade
- Drain repair or lining arranged where that is what caused it
- Surface reinstated — invisibly, where the surface allows it
What it costs
We don't publish a price for this yet, because a number pulled out of the air is worse than no number at all — your contractor has to honour it. On driveways it would also be close to meaningless: the groundworks are usually the biggest single factor, and how deep the dig has to go varies enormously house to house. You'll get a firm price for your actual job when they ring you back, before any work starts. The quote itself is free and there's no obligation either way.
Common questions
Is a sinking driveway a sign of subsidence in the house?
Usually not. A driveway sits on a shallow, lightly loaded construction of its own and settles for its own reasons — an old trench, poor compaction, a washed-out base. House subsidence shows up in the building: stepped cracking in brickwork, doors and windows binding, cracks wider at the top than the bottom. If you are seeing those as well as a sunken drive, that is a structural engineer's job rather than a driveway contractor's.
How do you know if a drain is causing it?
A camera survey, which is quick and inexpensive and settles the question rather than leaving it to guesswork. The pattern that raises the suspicion is a hollow over a known drain run, one that appeared quickly or keeps deepening, or one right beside a manhole. Relaying a drive over a leaking drain is work that will have to be done again.
Can the sunken area just be filled and topped up?
On gravel, yes. On anything else, no — filling a dip from the top leaves the void underneath and creates a thin, unsupported layer of surface material that will break up quickly. The area has to be lifted so the ground below can be excavated, filled and compacted properly. On block paving that is a straightforward job because the same blocks go back.
When should I stop parking on it?
If the hollow appeared suddenly, is deepening month by month, sounds hollow underfoot, or is directly over a drain or a manhole. That combination is consistent with a void beneath the surface, and voids fail all at once rather than gradually. Keep vehicles and people off it and get it opened up. A slow, stable settlement that has not changed in years is not that.
Need this doing in Macclesfield?
Tell us the job and it goes straight to our local contractor — one call back, usually the same day. Free quote, no obligation.