Rapid In-Situ Ground Stiffness and Compaction Assessment
Lightweight Deflectometer (LWD) Testing
Rapid In-Situ Ground Stiffness and Compaction Assessment
Lightweight Deflectometer (LWD) testing – sometimes referred to as Light Weight Deflectometer testing – provides a fast, practical way to assess ground stiffness and compaction performance directly on site. It’s ideal for formation layers, sub-bases and earthworks where timely verification is critical to keeping programmes on track and avoiding costly rework.
At Advantage Technical, we deliver LWD testing as part of our in-situ ground verification and earthworks testing services. Our technicians use calibrated equipment and consistent procedures to provide reliable, easy-to-understand results, helping contractors, engineers and clients make confident decisions in real time.
We operate nationally, with strong coverage across the South West and surrounding regions.
A Lightweight Deflectometer (LWD) is a portable dynamic loading device used to measure how the ground surface responds to a controlled impact. During the test:
Because testing is carried out directly on the formation or sub-base, there is no need to remove material or send samples away. Results are available immediately, allowing site teams to confirm whether layers meet specification before construction progresses.
LWD testing is widely used across highways, infrastructure and building projects for:
If your project requires frequent checks, multiple test locations or rapid decision-making, LWD testing offers a highly efficient solution.
Many engineers and contractors are familiar with plate bearing testing for assessing bearing capacity and stiffness. LWD testing does not replace plate bearing in every scenario, but it offers several important advantages for routine verification:
Where a specification explicitly calls for plate bearing tests, those requirements still apply. However, LWD is increasingly being specified as an alternative or complementary method, especially for earthworks and granular layers where speed and coverage are key.
LWD testing directly measures surface deflection and derived stiffness (dynamic modulus). Where helpful, we can also provide CBR-equivalent values, based on recognised correlations used widely in UK practice.
Our reports clearly distinguish between measured values and derived equivalents so there is no ambiguity for designers, contractors or auditors.
LWD testing carried out by Advantage Technical is aligned with recognised industry standards, guidance and manufacturer requirements, including:
Testing parameters such as drop weight, number of drops and data averaging are selected to reflect UK practice and individual project specifications, ensuring that results are both technically robust and practically useful.
Choosing Advantage Technical for your LWD testing provides a number of clear benefits:
At Advantage Technical, we deliver LWD testing with a site-focused, practical mindset:
Our goal is simple: to provide information that supports better construction decisions, not just to issue test reports.
Is LWD testing accepted instead of plate bearing?
It depends on the project specification. Where plate bearing is explicitly required, it must still be used. However, LWD testing is widely accepted for routine verification and quality control and is increasingly specified as an alternative or supplementary method.
Does LWD testing measure CBR?
No. LWD testing measures surface deflection and stiffness. CBR-equivalent values can be derived using recognised correlations where required, but these are not the same as laboratory-measured CBR tests.
How long does an LWD test take?
Individual tests typically take just a few minutes, meaning multiple locations can be assessed within a single working shift.
Can LWD testing be used on granular materials?
Yes. LWD testing is particularly well suited to granular materials such as Type 1 sub-base, capping layers and compacted fills.
Do the results need to be sent away?
No. Results are available immediately on site. Formal, collated reports are then issued after testing for your records and quality documentation.
If you’d like to discuss whether Lightweight Deflectometer (LWD) testing is suitable for your project – or how it can be used alongside existing requirements such as CBR or plate bearing tests – the team at Advantage Technical is ready to help.
We provide straightforward, practical advice based on your specification, ground conditions and programme, and can mobilise quickly to sites across the UK.
Advantage Technical
