Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust
  • Latest news

    25 Mar 2026

    BRE 365 Soakaway Testing

    Simon Ruddlesden was pleased to present at the AGS Annual Conference, to talk about BRE 365 soakaway testing, asking the question, though not necessarily providing the answer: Should we be carrying out BRE 365 soakaway testing in geologies where previous testing has shown soakaway/ infiltration drainage to be unsuitable? The BRE 365 soakaway test is widely accepted and requested as the field test that is to be carried out to assess the suitability of the ground for soakaway/ infiltration drainage. However, the test is not without danger, mainly due to working at height risks, and it is relatively wasteful of resources, including fuel and water. If previous testing results consistently and convincingly show that certain geologies are unsuitable for soakaway/ infiltration drainage, should a relatively unsafe and not particularly sustainable test be carried out? Using data from over 5,000 tests on more than 1,200 sites investigated by Ruddlesden geotechnical over the last 20 years, mainly in the South West, there is a clear and understandable correlation between unsuccessful tests and the underlying geology, where the underlying geology comprises predominantly lower permeability mudstones and clays, notably the Mercia Mudstone Group, Lias Group and Oxford Clay Formation, although there are a number of anomalies, which can usually be explained by a closer inspection of the local geology, including superficial deposits. More data and research will be required if regulators and designers are to accept that no testing is required in certain geologies. The presentation sparked an interesting discussion afterwards, and it is hoped that it will have inspired others to share their data and/ or offer technical support, to ultimately produce a map that provides confidence to regulators and designers that BRE 365 testing is not required in certain geologies. Please contact us directly if you would like to discuss this further.

    BRE 365 Soakaway Testing
    BRE 365 Soakaway Testing
  • Recent projects

    Foundation Inspections Reduce Construction Costs, East Devon

    Ruddlesden geotechnical are currently undertaking foundation inspections on a plot-by-plot basis for a regional housing developer at a new residential development site in East Devon. The consulting engineer had specified that all foundations be reinforced to accommodate local changes in the ground conditions, identified in the original geotechnical investigation. However, following a reduction in site levels, the majority of footings were to be founded in the relatively more homogenous underlying Dawlish Sandstone Formation and, where not encountered, it was found to be more cost effective to deepen foundations into the Dawlish Sandstone Formation, rather than reinforcing shallower footings, founded in the overlying superficial deposits. Ruddlesden geotechnical are responsible for providing an account of the ground conditions encountered in each foundation excavation and specifying whether further excavation (or reinforcement) is required for each plot.

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  • Recent projects

    Sand Replacement Testing Undertaken to Validate Earthworks, Torbay

    Following the production of an earthworks specification, Ruddlesden geotechnical undertook in-situ sand replacement testing, to confirm the dry density of compacted material, and collected representative samples for geotechnical laboratory testing, to confirm the moisture content and suitability of the compacted material, to validate the deposition of materials during the construction of an embankment. The embankment was being constructed as part of a larger earthworks scheme, which formed the enabling works for a residential development in Paignton. Liaison with the groundworkers and client was key to the success of the earthworks. Delays in material placement, particularly during periods of inclement weather, can lead to excessive time delays and hence additional costs.

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