Projects completedSince 2015
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The yellow line is a ground surface, drawn for illustration. The marker shows where a borehole goes in.
Ground investigation, est. 2015, Wigan
Know the ground before you build.
Ground investigation and soil testing, from a house extension
See what we doSee what we do
Talk to the officeFree, no-obligation quote
07518 458 787info@pmsampling.co.uk
About PM Sampling
Site investigation you can build on.
Since 2015, our drillers, engineering geologists and geotechnical and geo-environmental engineers have investigated the ground beneath construction projects of every size, in soil and in rock. We pick the method that suits your site, recover the samples, get them tested and give your engineer the information they need to design safely.
Typical figures. Every site differs.
0
0m
- Topsoil
- Made ground
- Clay
- Sand and gravel
- Rock
EstablishedWigan
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Our services
Eleven ways to understand your ground.
Every site is different, so we match the method to the access, the ground and what your engineer needs to know. Scroll through, or jump straight to a service.
- Site investigation The full picture
- Cable percussion drilling Boreholes up to 60m
- Rotary drilling and coring Rock and mine workings
- Window sampling Tight access
- Dynamic probing Blows per 100mm
- Trial pits See the strata
- Percolation testing Septic tanks
- Soakaway testing BRE 365
- Laboratory testing Soil and rock
- Contaminated land Brownfield sites
- Coal mining investigation Shallow workings
Soil. Rock. Water. Coal. Nothing assumed.
What we find
Every metre, logged.
As a borehole goes down, we describe each layer, take samples at set depths, carry out tests in the hole and note any water we meet. That record, the borehole log, tells your engineer what the ground can carry and how it will behave.
An illustrative log. Every site is different.
- 0.0m Topsoil
- 0.4m Made ground, brick fragments
- 2.1m Firm brown clay, sampled
- 6.5m Sand and gravel, water strike
- 11.0m Sandstone, cored
- Up to 60m Cable percussion
Who we help
Big or small, the same care.
We tackle any size of job, from a single soakaway test in a back garden to a full investigation for a commercial development, with the same attention to quality and value.
Homeowners and self-buildersExtensions and new homes
Foundation checks for building control, soakaway tests for drainage and window sampling where access is tight.
Do I need a soil test?
Architects and engineersData your design can rely on
Logged boreholes, in-situ tests and laboratory results, scoped to the questions your design needs answering.
Site investigation
Developers and contractorsWhole sites, done properly
Several rigs on one site, plus contaminated land, coal mining and drainage, from planning through to construction.
All servicesHow it works
From first call to final report.
- 01
Tell us about the site
Send the address, a plan if you have one and what you're building. We'll ask the right questions about access and services.
- 02
We plan the work
We propose the right mix of boreholes, probes, pits and tests, so you don't pay for more than you need.
- 03
We investigate
Our qualified drillers set up safely, recover samples, carry out in-situ tests and log everything they find.
- 04
You get the findings
Samples are tested and the results reported, so your engineer and building control have what they need.
Areas we cover
Based in Wigan, working across the North West.
Our rigs work across Greater Manchester, Merseyside, Lancashire and Cheshire. Every area has its own ground, from coal measures under Wigan to sandstone under Liverpool, and we plan for it.
Guides
Straight answers about your ground.
Plain-English guides to the questions we're asked most, from soakaway tests to coal mining risk.
Guide / DrainagePercolation tests explained
How the test works, what the Vp result means and what counts as a good result for a septic tank.
Read the guideGuide / HomeownersDo I need a soil test for an extension?
Why building control may ask about your ground, and the quickest way to answer them.
Read the guide
Guide / Coal miningDo I need a coal mining risk assessment?
What it means to build in a Development High Risk Area, and when drilling for old workings is needed.
Read the guideHow much does a ground investigation cost?
It depends on the size of the site, the number and depth of boreholes or pits, access and the testing needed. A single soakaway test or trial pit for an extension is a small job; a full investigation for a development is a bigger one. Send us the site address and what you're building and we'll give you a clear quote.
Do I need a soil test for my extension?
Often, yes. Building control may want to know the ground can carry your foundations, especially on clay, made ground or near trees, and if surface water is going to a soakaway they'll usually want a soakaway test. A trial pit or a window sample is often all it takes.
What's the difference between a percolation test and a soakaway test?
A percolation test checks whether the ground can take the treated water from a septic tank or treatment plant through a drainage field. A soakaway test, usually to the BRE 365 method, checks how quickly surface water from roofs and drives will soak away, so a soakaway can be designed.
Do you work outside Wigan?
Yes. We're based in Wigan and work across Greater Manchester, Merseyside, Lancashire and Cheshire. Tell us where your site is and we'll let you know.
Can you work in a back garden with no vehicle access?
Yes. Where access is too tight even for our compact rig, we use a hand-held window sampling system that recovers samples in the same tubes as the rig.