Ikoyi · 2025 · Residential
Lagoon-front housing estate
- Resistivity lines
- 12
- CPT soundings
- 8
- CPT depth
- 25 m
- Geophysical Survey
- Soil Investigation
Soil Investigation
Boreholes, in-situ testing and sampling to find out what is under your site.
Overview
Know the ground before you design the foundation.
A soil investigation tells your engineer what lies beneath the site: the soil layers, how strong they are, and where the water table sits. In Lagos, where loose sand often overlies soft clay and peat, it is the step that prevents redesigns and settlement later.
We plan borehole positions and depths around your building's loads, drill and test on site, and bring samples back to our laboratory for classification and strength testing.
- Stage
- 01 · Investigate
- Typical depth
- 15–40 m
- Lead time
- 2–6 weeks
Methods
How we investigate
Rotary and shell-and-auger boring
Cable-percussion and rotary rigs advance boreholes through sand, clay and weathered rock.
Standard Penetration Test (SPT)
Blow counts every 1.5 m give a measure of soil density and strength.
Undisturbed sampling
Thin-wall and piston samplers recover clay for laboratory strength tests.
Trial pits
Shallow excavations to inspect near-surface soils and existing foundations.
Cone Penetration Test (CPT)
A continuous profile of cone resistance and pore pressure with depth.
Groundwater monitoring
Standpipes record water levels for design and dewatering.
Standards
Standards we work to
- BS 5930Ground investigation
- BS EN ISO 22476Field penetration tests
- ASTM D1586Standard Penetration Test
Deliverables
What you receive
Borehole logs
Depth, strata, SPT N-values and groundwater for every borehole.
Factual report
All field and laboratory results, presented without interpretation.
Interpretative report
The ground model and design parameters, interpreted by an engineer.
Recommendations
Foundation options, bearing capacity and pile design input.
Ground conditions in Lagos
Why investigation depth matters here
Low-lying coastal areas such as Lekki, Victoria Island and Ikoyi are commonly reported to have sand over soft compressible clay and peat with a high water table. That is why boreholes often need to go past 30 m, and why piled foundations are common.
- 0–1.5 mMade ground, loose sand
- 1.5–6 mLoose silty sand
- 6–14 mSoft clay with peat
- 14 m +Dense sand
Related projects
Soil investigations we have delivered
Ibeju-Lekki · 2024 · Industrial
Logistics warehouse
- Boreholes
- 10
- Max depth
- 20 m
- Lab tests
- 120
- Soil Investigation
- Soil Testing
- Geotechnical Service
Lekki Phase 1 · 2024 · Residential
10-storey residential block
- Boreholes
- 6
- Max depth
- 35 m
- Lab tests
- 48
- Soil Investigation
- Soil Testing
- Geotechnical Service
FAQ
Soil Investigation questions
Can't find your answer? Send us a message and an engineer will reply.
Deep enough to pass through soft or loose layers into firm ground below the zone your foundation will load. In much of Lekki and Victoria Island that means 30 m or more; an engineer sets the depth for your building.
Request a quote
Planning a build in Lagos? Start with the ground.
Tell us where the site is and what you plan to build. An engineer will come back with a proposed scope of investigation and a quote.