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Method Statement – Granular Sub-Base (GSB) Installation (Type 1 / Type 2 Unbound Mixtures) inspection and test plan example.

Inspection and Test Plan for Method Statement – Granular Sub-Base (GSB) Installation (Type 1 / Type 2 Unbound Mixtures)

AI-assisted inspection and test plan connected to a method statement, with PDF and Excel export.

Published 27 Jun 2026 Rev. 00 2 views
About this ITP: This ITP defines inspections, tests, and records for GSB works, including material verification, compaction control, density/moisture testing, and survey tolerances.

More than a static template

Unlike a downloadable Word or PDF template, this ITP is an AI-assisted editable starting point directly connected to its method statement. Every inspection activity, hold point, and acceptance criterion is structured and ready to adapt to your project.

  • AI-assisted customization — Tailor inspection activities and acceptance criteria to your specific project scope.
  • Linked method statement — This ITP is connected to the corresponding method statement describing the work sequence.
  • Multiple export formats — Download as a formatted PDF or editable Excel spreadsheet.
  • Editable starting point, not a final document — Review and verify all content against your project specifications and standards before use.

What you can customize

When you save this ITP to your account, every inspection row becomes editable. You can add, remove, or modify:

  • Inspection activity — Description of what is being inspected.
  • Inspection type — Hold point (H), Witness point (W), Review (R), or Monitor (M).
  • Responsibility — Contractor, subcontractor, engineer, or client.
  • Frequency — How often the inspection occurs.
  • Acceptance criteria — Referenced standard or specification requirement.
  • Records — Forms, test reports, or checklists required as evidence.

Why this ITP is used

To systematically verify that GSB layers meet material, compaction, and geometric tolerances prior to overlying works.

Who uses this inspection and test plan

Contractor QA/QC and Site Teams, Independent Laboratories, and the Engineer/Employer’s Representative.

When this ITP is prepared and submitted

Applied for each lot/layer of GSB during and after placement until final acceptance.

Who receives or approves this ITP

Engineer/Employer’s Representative for approval and lot acceptance.

Inspection scope

Covers material delivery, formation approval, spreading, moisture conditioning, compaction, field density, surface regularity, cross-fall, thickness, and documentation.

Typical hold, witness, and review points

Formation approval (Hold), field density tests (Hold), thickness checks (Hold), surface/cross-fall survey (Witness), compaction operations (Witness).

Typical inspection records

Material certificates, delivery tickets, density/moisture reports, survey logs, straightedge records, roller pass logs, IR approvals, NCR/CAR (if any).

Important approval note

This ITP is an AI-assisted editable starting point, not a pre-approved document. Before use on any project, all inspection activities, hold points, and acceptance criteria must be reviewed and approved by the relevant parties (superintendent, principal contractor, or client representative) in accordance with your contract and project quality plan.

Always verify acceptance criteria against your applicable drawings, specifications, and regulatory requirements. Hold points must be confirmed with the relevant authority before work proceeds past that point.

Inspection and test plan

Activity Inspection / Test Acceptance Criteria Responsibility Record
Material delivery and certification Check CoC/DoP; verify source and grading certificates Material complies with BS EN 13285/13242 and approved submittal QA/QC Engineer Material approval; delivery tickets; certificates
Stockpile condition and segregation control Check separation by type/lot; no contamination; drainage in place No cross-contamination; minimal segregation; controlled height/slopes Foreman / QA/QC Stockpile inspection log
Formation approval / geotextile installation (if required) Survey levels; proof-rolling; visual checks; geotextile overlaps Firm, stable formation; levels within tolerance; geotextile overlapped ≥300 mm and secured Site Engineer / Engineer (Witness) IR approval; survey report; photos
Setting out and control Instrument calibration; check control points Calibrations valid; control within allowable closure Surveyor / QA/QC Calibration certs; setting-out sheets
Layer spreading (pre-compaction) Loose thickness checks; segregation checks Uniform loose thickness (typically 150–200 mm); no visible segregation Foreman / Site Engineer Daily diary; thickness logs
Moisture conditioning Moisture content checks (meter/oven) -2% to +1% of OMC at time of compaction [Verify] QA/QC / Foreman Moisture test reports
Compaction operations Roller pass log; check for movement/pumping No visible deformation/pumping; full coverage including edges Foreman / QA/QC / Engineer (Witness) Roller logs; photos
Field density and moisture testing NDG (ASTM D6938) or Sand Cone (ASTM D1556); moisture test ≥95% of MDD (BS EN 13286-2/ASTM D1557); moisture within specified range Lab Technician / QA/QC Field density/moisture reports
Surface level, regularity, and cross-fall survey 3 m straightedge; total station/laser survey grid Level ±10 mm; 3 m straightedge ≤10 mm; cross-fall within ±0.3% [Verify] Site Engineer / Surveyor Survey report; straightedge log
Thickness verification Test pits/cores or level delta between formation and GSB Average thickness ≥ design; local -10 mm/+15 mm [Verify] QA/QC / Engineer (Witness) Thickness report; photos
Final inspection and lot acceptance Review all test results and as-built All ITP items closed with acceptable results QA/QC / Engineer IR sign-off; lot acceptance certificate

This table is a read-only public reference. Download the PDF or Excel version, or customize this ITP to edit it for your project.

Frequently asked questions

Use a single approved method across the project—either NDG (ASTM D6938) with valid licensing or sand cone (ASTM D1556). The choice must be approved in the ITP.

By chainage/area and by day’s production. Each lot should be traceable to specific test results, roller logs, and survey data.

After any rectification (rework, moisture conditioning, or additional compaction) or when a test result is below acceptance limits.

Related method statement

This Inspection and Test Plan is associated with the Method Statement – Granular Sub-Base (GSB) Installation (Type 1 / Type 2 Unbound Mixtures) method statement, which describes the step-by-step construction sequence, resources, materials, equipment, safety controls, and environmental controls for this activity.

View the Method Statement – Granular Sub-Base (GSB) Installation (Type 1 / Type 2 Unbound Mixtures) method statement →

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