We test across Solihull and the villages of the Arden area regularly, from Shirley out to Balsall Common. We carry out BRE365 soakaway percolation testing and BS 6297 foul infiltration testing across Solihull and the surrounding area.
We have tested 10 sites within five miles of Solihull, 32 within ten and 150 within twenty-five, so the ground here is familiar to us. Of the 32 tests within ten miles, 29 gave a usable result and 3 showed infiltration too poor for a soakaway, which is exactly why a test is needed before the design is fixed.
Ground conditions in Solihull
Most of Solihull sits on the Mercia Mudstone, the red clay-rich rock once called Keuper Marl, often with a cover of glacial clay. Thin sandstone bands, such as the Arden Sandstone, run through it in places, and there are pockets of glacial sand and gravel.
Mudstone and clay rarely take water quickly, so it is common for a Solihull site to show slow infiltration or to fail the test outright. That is not a wasted test: it is the evidence the Council needs to accept an alternative such as attenuation and a controlled discharge. Knowing early saves redesigning the drainage after the groundworks are priced.
What we test for
- BRE365 percolation testing for surface water soakaway design
- Foul effluent infiltration testing (Part H) for septic tanks and treatment plants
- Drainage strategy (SuDS) support for planning applications
How the test is carried out
BRE Digest 365 sets out the procedure. A single filling of a single hole proves very little.
- Trial pits are dug at the proposed soakaway position, taken below the level the soakaway will sit at.
- Each pit is filled to at least 75% of its effective depth, where the timed measurement starts.
- Each pit is filled and timed three times, measuring the fall from 75% to 25% of the effective depth.
- The slowest run is used in the calculation, which keeps the design conservative.
Planning conditions in Solihull
Applications are determined by Solihull Metropolitan Borough Council, which is also the Lead Local Flood Authority. The Council expects the drainage hierarchy to be followed, so infiltration has to be tested and ruled in or out before a sewer connection will be accepted.
Testing early is worth it. If infiltration is not viable the drainage strategy has to change, and finding that out after the groundworks are priced is an expensive surprise.
Foul drainage and septic tanks
If the site is not on mains foul drainage, that is a separate test. Drainage fields for septic tanks and package treatment plants are sized by the method in BS 6297, referenced by Part H of the Building Regulations, and that figure is not interchangeable with a BRE365 result. We can carry out both on the same visit.
What you receive
- A full report with the recorded times for every pit and every fill
- The calculated infiltration rate, ready for your engineer or planner
- Trial pit locations and depths
- Photographs of the testing on site
- A clear statement of whether a soakaway is viable, and if not, why not
Coverage
We cover the whole of Solihull, including Shirley, Knowle, Dorridge, Balsall Common, Hampton-in-Arden, Meriden and Olton. Available Monday to Friday.
Get a quote
For a free, no-obligation quote, call 01902 475653, send an enquiry, or if you know where the pits need to go, use our detailed quote request.
Percolation testing around Solihull
Each dot is a site we have tested. 32 within ten miles of Solihull, 150 within twenty-five.
Also serving the West Midlands
This page is part of our coverage across the West Midlands, which also includes: