How far should a soakaway be from a building?

A soakaway must always be the first choice but must not be used: Within 5m of a building or road, 2.5m of a boundary or in an area of unstable land in ground where the water table reaches the bottom of the soakaway at any time of the year.

How do you design a soakaway?

The design method for sizing a soakaway is based upon the equation of volumes: I – O = S where: I = the inflow from the impermeable area drained to the soakaway; O = the outflow infiltrating into the soil during rainfall; S = the required storage in the soakaway to balance temporarily inflow and outflow.

What size does a soakaway need to be?

1 Cubic Metre
What Size Should My Soakaway Be? The most common size of soakaway for residential use is 1 Cubic Metre (1m³), as this is what most Local Authorities seem to specify. As a broad brush a Soakaway Size of 1m³ is sufficient to drain a roof area of approximately 50 square metres under normal conditions.

Can a soakaway be less than 5m?

Soakaways must be located in such a way that they don’t pose an unacceptable risk to any building and its foundations. A minimum of 5m of separation is required by the British Standard & Building Regulations.

How deep does a rainwater soakaway need to be?

3 – How Deep Should a Soakaway be? There is no minimum or maximum depth. The amount of water the soakaway can hold and how quickly (or slowly) the water seeps away into the ground are the critical factors, not vertical depth or horizontal spread.

How close to a boundary can a soakaway be?

2.5 meters
A soakaway must be 2.5 meters from the boundary. The soakaway must not be in an area of unstable ground or where the lowest point of the soakaway meets the water table at any point of the year. The soakaway must not be near any other soakaway or drainage field, as this would compromise the absorption of the ground.

How far below ground should a soakaway be?

Soakaways should be: sited at least 5m from the foundations of a building. sited to take account of topography, ensuring that water is drained away from the building. in soil of low permeability, only be provided where no alternative system is available.

How deep should a soak pit be?

Drill a test hole 100–150 mm in diameter for the expected depth of the soak pit. If groundwater is struck before the expected depth is reached, the depth of the ground water is taken as the maximum depth of the soak pit. Fill the hole with water and maintain it for at least 4 hours to presoak the ground.

How deep should a soakaway be in clay soil?

1.8m deep
A soakaway is basically a deep hole filled with rubble. To work, it must extend below the clay and be at least 1.8m deep. Dig a series of parallel trenches every 3-6m across the garden, sloping towards the ditch or soakaway.

Where do you put a soakaway?

Location of your soakaway We would not recommend installing a soakaway in clay soil as clay does not allow water to drain through it. The ideal site is in ground that is at a lower level than that of the building, or at very least on the same level.