Drainage & Levelling
Stop water pooling on your patio and slabs sitting uneven, fixed at the sub-base, not just the surface.
What Goes Wrong
Patching the surface without addressing the sub-base means the same puddles return within a season.
Older Cambridge properties often have patios laid without any fall, so water sits against the house wall rather than running clear.
Slabs are lifted and relaid to a 1 in 60 gradient, checked with a laser level before jointing begins.
Cambridge clay shifts seasonally, causing the base beneath slabs to sink unevenly and creating low spots that collect standing water.
The settled base is broken up, re-compacted to the correct depth and rebuilt before a fresh bedding layer is set.
Cambridgeshire frost cycles push slabs upward and wash joint sand out, leaving edges that catch feet and gaps that let water in.
Affected slabs are lifted, the bedding reset, and joint sand brushed back in after compaction to lock the surface stable.
Where the surface fall alone cannot shift enough water, there is nowhere for it to go and puddling becomes a permanent feature.
An ACO channel drain or surface drain is set at the low edge and connected to a soakaway, gully or boundary outlet.
Scope of Work
From a single sunken slab to a full surface regrade, the work is scoped to the actual cause, not a standard package.
Laser level used to map existing fall; slabs lifted and relaid to a gradient that sheds water away from the house.
Settled or inadequate base broken out, re-compacted and rebuilt to the correct depth before slabs are relaid.
Individual sunken or rocking slabs lifted, bedding corrected and slabs reset flush with surrounding paving.
ACO channel drain or surface drain set at the low edge and connected to a suitable outlet, soakaway, gully or boundary.
Brushed back in after compaction to lock slabs stable.
Moved or lifted edging checked and reset during the relay.
Channel drain tied into soakaway, gully or boundary drain.
Why Choose Us
Drainage and levelling jobs go wrong when the diagnosis is skipped, here is how we make sure that does not happen.
A site visit assesses fall direction and sub-base condition before quoting or starting work.
Fall direction is checked on arrival and again after relaying, so the finished surface meets the 1 in 60 target.
Excavation, sub-base, bedding and drainage are quoted as separate lines so you see exactly what you are paying for.
Every survey accounts for how seasonal clay movement and frost cycles affect sub-base depth and compaction requirements here.
Work targets the sub-base or fall direction, not a surface patch that leaves the underlying problem in place.
Pricing Estimates
| Job | Typical cost | Typical scope |
|---|---|---|
| Minor levelling | £300-£800 | Small area |
| Drainage correction | £600-£1,800 | Localised issue |
| Levelling and drainage for a full patio | £1,500-£4,000 | Whole patio |
Common Questions
Water pools when the surface fall runs toward the house or a low spot rather than away from it. This is usually caused by settlement, a poorly set original fall, or a sunken slab creating a hollow. Even a few millimetres of dip is enough to hold standing water after rain.
If water sits on the surface for more than an hour after rain, or runs toward the house wall, the fall is wrong and needs correcting. Visible dips, rocking slabs, or puddles that form in the same spot every time are the clearest signs. A survey will confirm whether the base or the surface is the root cause.
Yes. A dip of as little as 10-15 mm across a slab is enough to hold a puddle. Water always finds the lowest point, so even a shallow hollow collects and holds standing water rather than shedding it to the edge.
Correcting the fall addresses both issues at once in most cases. Once the surface sheds water consistently toward a drain or lawn edge, pooling stops and the level reads flat underfoot. Where a drain is blocked or absent, a channel or point drain may also be needed alongside the re-levelling work.
Yes, once the mortar or bedding has cured fully and joints are set, the surface is safe to walk on. The curing time is confirmed on the day, typically 24-48 hours for mortar beds before normal foot traffic resumes.
Yes, provided the fall is set to a minimum 1:60 gradient away from the building, surface water drains clear of the house wall. This is the standard fall used when resetting patio slabs close to a property. A survey confirms the correct direction and gradient for your specific layout.
In most cases, yes. Lifting and resetting the affected slabs with a corrected bed and fall is enough to solve pooling and uneven surfaces. Full replacement is only necessary when the base has failed across the whole area or the slabs themselves are cracked beyond reuse.
The installer sets a consistent fall across the reset area, checks levels at every slab join, and confirms water tracks to the intended outlet before finishing. Where the base was the root cause, it is compacted or rebuilt to the correct depth so the slabs have a stable, uniform platform.
Describe the garden, what is down there now and how it drains. We will schedule a survey and quote the work properly.