Attenuation tank installer in Solihull

The M42 corridor

The M42 runs straight through Solihull, and the land beside it carries business parks, offices, hotels and industrial units. These sites have large roofs and wide car parks, which means a lot of hard surface shedding water fast. The tank usually sits under the car park or the service yard, built to a highway loading class.

From our Tamworth base, the M42 brings us straight down to these sites, so early starts and a quick return visit for a late connection are easy to arrange.

Commercial sites here are often occupied or next to occupied units, with staff traffic and deliveries going on around the works. We keep our materials and working area inside the groundworker's fenced zone and work to the site's own access rules.

Housing on the edge of the borough

New housing in Solihull tends to come as extensions to existing villages and suburbs, or as larger schemes on the edge of the built-up area. The attenuation is often a run of crate tanks under open space or estate roads, sometimes alongside a surface basin, with the engineer splitting the storage across several locations to suit the levels.

Several tanks on one estate means several sets of connections and several weld records. We keep each tank's QA record separate so the documentation lines up with the drainage layout when the roads and sewers go for adoption.

Clay ground and two small rivers

Most of Solihull sits on clays that drain poorly, which rules out soakaways on many sites. Runoff from the borough heads for the Blythe and the Cole, both small rivers that rise quickly in heavy rain. That is why discharge rates here are kept tight, and why the storage behind the flow control has to be watertight to do its job.

A tank that leaks into clay doesn't drain away. The water sits around the crates, softens the ground and can find its way into trenches and foundations nearby. Welded seams and a tested membrane stop that happening.

• Tanks under car parks and yards built to highway loading
• Multiple tanks on one estate, each with its own QA record
• Supply and install, or install only with your materials
• Fleece, membrane and heat-welded seams on every tank

How the job runs

Sizing and design sit with your drainage engineer, and the excavation sits with your groundworker. Our part starts at the formation check: fleece and membrane go down, the crates (95–97% void) go up inside them, the connections are formed and a test weld is made and logged. Then the groundworker backfills, and you have the handover pack for building control.