Soakaway Installation in Coventry

Signs Your Soakaway Is Failing

A soakaway fails silently for a while before it becomes obvious. The indicators to watch for are:

• Water pooling on paths or lawn near the downpipe connection — the most direct sign that water is no longer dispersing underground and is instead backing up to the surface.
• Soggy ground that doesn't fully dry between rain events — a soakaway that has silted up retains water rather than dispersing it, keeping the surrounding soil persistently waterlogged.
• Surface water flowing onto the pavement or neighbour's property — once a soakaway is overwhelmed, water finds the path of least resistance, which is often over a driveway or across a boundary.
• The soakaway chamber full to the brim after rainfall — if the chamber is accessible and fills up without draining down within a few hours, either the soakaway has silted up internally or the surrounding soil is no longer permeable enough to accept the volume.

What We Do Before Installing

Installing a soakaway without testing the ground first is a shortcut that leads to a second failure within a few years. Before we quote for a new or replacement installation, we carry out:

• Percolation test — we dig a test pit to the proposed soakaway depth, saturate it with water, and measure the rate at which the water level drops. BRE Digest 365 specifies the test method. If the percolation rate is too slow — as it can be in the clay-heavy soils on some parts of the city — we will tell you before you pay for an installation that won't work.
• Assessment of the existing soakaway — if there is already a soakaway on site, we inspect it to understand whether it has silted up (cleanable or replaceable) or whether the surrounding soil has become permanently saturated (a site suitability problem rather than a maintenance one).
• Correct sizing calculation — the soakaway volume is calculated from the roof or surface area draining into it and the measured percolation rate. We do not guess the size.
• Position check — Building Regulations require a 5-metre setback from building foundations. We confirm the proposed position meets this before quoting.

Installation

Where an existing soakaway has failed, we excavate and remove the old crate or rubble fill before installing the replacement. A modern plastic crate soakaway has a significantly greater void volume than the rubble-filled pits common on Coventry's post-war estates — which means it can accept larger volumes of water and disperses it more evenly. We wrap the crate in a non-woven geotextile membrane to prevent silt migration from the surrounding soil, connect it to the existing downpipe or surface drain, and backfill and compact properly.

The connection to the downpipe is made with proper drainage fittings — not push-fit garden pipe, which separates under ground pressure.

When a Soakaway Won't Work

Some areas of Coventry sit on heavy clay subsoil that does not achieve the percolation rate required for a soakaway under BRE Digest 365. If the percolation test shows the soil is too impermeable, we will explain this clearly rather than install a soakaway that will fail again within a few years. In these cases the realistic alternative is connecting the surface water to a suitable surface water drain — which may require an application to Severn Trent or the local authority depending on the discharge point.

For issues with your existing surface drainage, see our outside drain blocked and domestic drainage services. For other drainage repairs around the property, we cover the full range.