Driveway base and groundwork: what needs assessing before resin

Record observations without diagnosing the base

Make a simple sketch showing the current surface, parking area, paths, entrance and anything excluded from the project. Photograph cracks, patches, depressions and edges from both close up and further away. Note whether a problem appears to be changing and whether water collects after rain. Describe what you can see rather than labelling the cause as settlement, failed drainage or tree-root damage without an assessment.

Tell the contractor about previous repairs, known service routes and any construction records you hold. Mention vehicles and delivery requirements, including occasional heavier loads. Where information is missing, mark it unknown. An honest gap in the brief is more useful than an assumed base depth or a guessed description of buried materials that later becomes part of the pricing assumptions.

Ask what makes the overlay proposal defensible

Reusing an existing base is a construction option to assess, not a default saving. Ask who checks its condition, stability, compatibility with the proposed resin system and ability to accommodate the intended loading. If repairs are proposed, request their locations and method in writing. Find out how existing joints will be dealt with and whether any underlying movement could affect the new finish.

Levels matter even when very little is removed. Adding a finish changes relationships with door thresholds, garages, access covers and neighbouring surfaces. Ask for the proposed finished levels and edge transitions, and how these interact with damp protection and drainage. Do not accept a verbal assurance that an extra layer is thin enough without understanding the details at the most constrained points.

Understand the rebuild as a sequence of responsibilities

For a rebuild, request a description of removal, excavation, formation preparation, sub-base, any intermediate base and the resin finish. The required materials and depths must follow the site assessment and specified system. There is no single universal build-up in this guide. Ask how excavated material will leave the property, where machinery can operate and who arranges any necessary permissions for site logistics.

The government's permeable-surfacing guidance explains that drainage-related sub-base materials differ from conventional dense materials containing fines. That distinction is useful when reading a quote, but a material name alone does not establish a functioning drainage design. Ask how the complete construction will support vehicles and handle rainfall, including any storage, infiltration or proposed discharge route.

• Confirm access width, carrying distances and temporary parking arrangements.
• Identify covers, thresholds, boundaries and existing drainage to retain or alter.
• Ask who checks for services before intrusive work begins.
• Request a written process for unexpected conditions and authorised variations.

Make uncertainty visible before accepting a total

A quote may include provisional work because the contractor cannot inspect every buried condition beforehand. Ask which assumptions remain unconfirmed, what investigation is proposed and how extra work would be priced. Agree who must approve a change and how the revised cost and programme will be recorded before the work proceeds. An unspecified allowance should not quietly become an unlimited commitment.

Finally, request inspection or photographic records for stages that will be covered up. These do not independently certify construction quality, but they help document what was agreed and carried out. Keep the base proposal alongside the surface specification when comparing quotations. If one price retains the existing base and another removes it, resolve the reason for that difference before judging either total.