Build Over Drainage Survey in Trentham
Comprehensive pre-build drainage survey carried out at a residential property ahead of proposed construction works.
The survey was undertaken to assess the condition, layout and accessibility of the existing drainage network, identify defects that could affect the proposed build, and establish which sections required further investigation before construction began.
Location: Stoke-on-Trent, Staffordshire
Service: Build over drain survey
Overview
We were instructed to carry out a pre-build drainage survey at a residential property ahead of proposed construction works.
The purpose of the survey was to understand the layout and condition of the existing drainage infrastructure within and around the proposed development area, identify any defects that could affect the build, and confirm whether the drainage system could be fully inspected before works commenced.
Build over and pre-construction drainage surveys are particularly important where existing drainage runs may pass beneath or close to proposed foundations, extensions or other building works. Identifying defects and access limitations before construction helps reduce the risk of unexpected drainage problems once the build is underway.
What we did
We carried out a comprehensive CCTV drainage survey across the accessible drainage network serving the property. The survey included:
Inspecting accessible drainage runs using CCTV equipment
Confirming drainage routes and connectivity where possible
Assessing the structural condition of the pipework
Identifying blockages and restrictions affecting camera access
Recording defects within off-boundary drainage sections
Establishing which drainage runs required cleaning and reinspection
Providing recommendations before construction works progressed
Several drainage runs contained significant accumulations of debris. In some locations, this prevented the CCTV camera from progressing further through the pipework, meaning sections of the survey had to be abandoned. As a result, the complete route, connectivity and condition of these sections could not be confirmed during the initial inspection.
Outcome
The survey identified several issues requiring attention before the proposed construction works progressed.
The drainage line extending off-boundary from one of the manholes contained a number of displaced joints and areas of cracking. A collapsed section of pipework was also identified further along this run, preventing CCTV inspection beyond the defect.
The downstream drainage run from another manhole was also affected by debris. The obstruction prevented further camera progress, meaning the continuation, route and condition of the remaining downstream pipework could not be established.
Based on the findings, we recommended:
High-pressure water jetting of all obstructed drainage runs
Clearance of debris preventing CCTV access
Reinspection of previously inaccessible sections
Confirmation of full drainage routes and connectivity following cleaning
Further structural condition assessment before construction begins
Reporting the off-boundary collapsed pipework to the relevant water authority
Highlighting the associated displaced joints and cracking to the water authority
Completion of any necessary remedial works before construction progresses
The collapsed off-boundary section was an important finding, as defects within shared or public drainage infrastructure may require investigation and repair by the relevant water authority rather than the homeowner.
Following cleaning and any required remedial works, we recommended a further CCTV inspection to confirm the condition and continuity of the previously inaccessible drainage runs and determine whether any additional repairs would be required.
This project is a strong example of why build over and pre-build drainage surveys should be completed before construction begins. Where debris, collapsed pipework or structural defects prevent a full inspection, identifying these issues early gives homeowners, architects and contractors the opportunity to resolve them before access becomes more difficult once building works are underway.
Location
This project was carried out at a residential property in Trentham, Stoke-on-Trent, ahead of proposed construction works affecting shared and private drainage infrastructure.
We regularly undertake build over CCTV drainage surveys across Trentham, Stoke-on-Trent, Newcastle-under-Lyme, Stone, Stafford and the wider Staffordshire area, helping homeowners, architects and contractors assess drainage condition, identify defects and support water authority approval before building works begin.