Drainage & FoundationsSpecialists in Burntwood

What the work covers

Strip and trench-fill foundations, footings for extensions and outbuildings, foul and surface water drainage, soakaways and land drainage, inspection chambers and connections, excavation, muck away and backfill, and compacted sub-bases and oversites. It is the detailed end of our groundworks trade, the elements where depth, fall and compaction decide whether the job lasts.

Most groundworks problems come back to two things: a foundation that was not taken deep enough, or drainage laid to the wrong gradient. Both are invisible once the job is finished and expensive once they fail, so both are worth doing slowly.

Who it is for

Homeowners building an extension, garage, garden room or outbuilding that needs proper footings. Anyone with drainage that backs up, ponds, smells or has to be rodded repeatedly. People with standing water against a wall or a soakaway that has stopped soaking away. Self-builders who need the below-ground package taken from setting out to oversite. And owners of older properties where the existing drainage layout is largely unknown until it is opened up.

When it is needed

At the start of any build, because foundations and drainage precede every other trade and hold up the whole programme if they are wrong. Also reactively: a gully that will not clear, a chamber surcharging, a patio that has dropped away from the house, cracking at openings that suggests movement below, or water appearing at a wall that used to stay dry.

Autumn and winter are the honest test. If water stands somewhere it never used to, something in the ground or the drainage has changed, and investigating before the wet season is easier than during it.

Why professional work matters

Foundation depth is a judgement made in the trench, not on the drawing. Cohesive clays shrink and swell with moisture, and nearby trees extend that zone considerably, so depth follows what the excavation actually reveals. Drainage has to be laid to a fall that carries solids without outrunning the water, bedded and surrounded so it is supported evenly, and connected so it can be accessed later.

This is also inspected work. Foundations and drainage on notifiable projects are checked at trench stage and at test stage, before they are covered. Getting it right first time is the difference between a signed-off job and one that comes back up.

Set out, then dug

Levels and falls are set out and checked before the digger starts. Pipework is bedded and surrounded the way it should be rather than dropped onto spoil.

Ducting planned in

Because we also do the electrical work, supplies and ducting can go in while the trench is still open instead of being dug up again later.

Materials and methods

Strip foundations are a concrete base with masonry built up off it; trench fill brings concrete close to ground level and is often the sensible choice in deeper digs because there is less below-ground brickwork to build. Depth follows the soil: clays need to be below the seasonally active zone, and mature trees push that requirement deeper again.

Drainage is laid in plastic or clay pipe on a granular bed with the correct surround, foul and surface water kept separate, and inspection chambers placed at changes of direction and junctions so the run can be accessed. Soakaways are sized for the area draining to them and sited well away from foundations. Sub-bases are graded stone laid and compacted in layers, with a geotextile separator where the subgrade is soft. Ducting is drawn in and capped before backfill.

Variations of the work

Footings for extensions, garages, garden rooms and outbuildings. Full below-ground packages taking a build from clearance to oversite. Single-item drainage work: a new gully, a connection into an existing chamber, a soakaway to take roof water away from a wall, or land drainage for a garden that will not dry out. Slabs for workshops, garages and hot tubs. And remedial work, finding why a run keeps blocking, correcting a fall, or re-laying a section that was never bedded.

Situations this applies to

Clay sites with mature trees, where depth is the whole question. Extensions that must tie sensibly into existing foundations and existing drainage. Drives and patios where the finished level has to work with thresholds and falls. Restricted-access sites where machine size and muck away dictate the sequence. And older properties where the drainage layout is partly unknown until the ground is opened.

Domestic and commercial differences

On domestic work the constraints are access, spoil containment, keeping a drive usable and keeping the house drainage in service while it is altered. Commercial and main-contractor work adds programme dates, fixed inspection windows and documentation for the principal contractor. The setting out and compaction discipline does not change.

Because electrical work is in-house, external supplies, charge point feeds and duct runs are co-ordinated with the dig rather than negotiated after the ground has been closed.