What is a Bre 365 test?
BRE 365 Percolation Tests follow the guidance of the Building Research Establishment (BRE). The process will calculate the Soil Infiltration Rate, which then allows us to calculate the size of any proposed Soakaway or other infiltration device, based on a 1 in 100-year storm event plus 40% climate change allowance.
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 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 is the standard size of soakaway?
1 Cubic Metre
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.
How far does a soakaway have to be from a boundary?
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 is percolation test calculated?
Determine the percolation rate by refilling each hole with water to a depth of at least 300mm and observe the time in seconds for the water to seep away from 75% full to 25% full (i.e. a depth of 150mm). 6. Divide this time in seconds by 150. This gives the average time in seconds required for the water to drop 1mm.
What are the requirements for a soakaway?
A soakaway must have capacity to store immediate run-off from roofs and hard surfaces and the water must then be able to disperse into the surrounding soil quickly enough for the soakaway to be able to cope with the next storm.
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 far from a building should a soakaway be?
What is a good percolation result?
between 15 and 100 seconds
Vp = The speed at which the water in the test holes percolates through the soil. Any result between 15 and 100 seconds means that the ground should be suitable.
What is a good percolation rate for soil?
between 10 and 60 minutes per inch
For soils to effectively treat effluent, percolation rates must be between 10 and 60 minutes per inch of percolation. You need at least 20 to 21 hours to do a standard percolation test requires.
Do you need permission to install a soakaway?
Permission’s needed depends on the type of soakaway you are intending to build. For a septic soakaway, drain field, or Sewerage treatment plant soakaway you will need planning permission. Unless it is a direct replacement. For a Rainwater Soakaway, you should consult your local planning agency.
Should rainwater go into septic tank?
Make sure that your downpipes and drains that carry rainwater are not connected to your septic tank. This could wash out the contents of the tank before it is broken down, and could cause pollution and health hazards.
What is Bre 365 and Bre 151?
First published in 1991 as a replacement for the old BRE 151, BRE 365 has become the standard methodology for soakaway design in the UK. It includes design guidance for soakaway pits, trench soakaways and general advice for soakaway crates.
What is BRE Digest 365 and why is it important?
BRE Digest 365 is one of the most regularly used design guidance reports issued by the Building Research Establishment. First published in 1991 as a replacement for the old BRE 151, BRE 365 has become the standard methodology for soakaway design in the UK.
What is Bre 365 testing for a soakaway?
That’s where BRE 365 testing comes from. To meet these standards, soakaways must be able to show that water stored within it drains quickly enough so that it can still provide the necessary run-off support for subsequent torrential rainfall. According to the Digest, soakaways should discharge from full to half-volume within 24 hours.
How do you test for bre365?
To test to BRE365 involves the following: First, a trial pit is excavated. This pit acts as a sortof replica of the intended soakaway. These trial pits can be dug by hand, but tend to be excavated by mini-diggers ( CAT or JCB ). This pit is then filled with water repeatedly, and in a short space of time.