Drain Survey Case Studies

Victorian Terrace — Islington N1

A homebuyer instructed us to carry out a pre-purchase drain survey on a Victorian mid-terrace in Islington before exchanging contracts. The property had no visible drainage issues, but the vendor had mentioned occasional slow drainage in the ground floor bathroom.

Our CCTV survey revealed a displaced joint 4.2 metres from the inspection chamber, combined with significant root ingress from a street tree under a Tree Preservation Order. The root mass had reduced the pipe's internal diameter by approximately 60%. This finding was critical: the TPO prevented treatment of the root source, meaning the affected section needed relining.

The buyer used our report to renegotiate the purchase price, achieving a reduction that covered the full relining cost with margin to spare. The report was accepted by their solicitor and mortgage lender without question.

Georgian Townhouse — Westminster SW1

A property management company asked us to survey a Georgian townhouse divided into five flats in Westminster. Long-running disputes between residents about drain maintenance responsibility had created tension, and the freeholder needed an authoritative assessment of the drainage system before a major refurbishment.

Our survey mapped the complete drainage layout of the building including shared and private runs. We identified two collapsed sections in the shared stack serving the upper floors and a fat and grease buildup in the combined drain serving the ground floor restaurant. The WRC-graded report provided the freeholder with the evidence needed to apportion maintenance responsibility fairly and to obtain accurate contractor quotes.

Commercial Office — Southwark SE1

A commercial tenant commissioned a drain survey before taking a new lease on a ground-floor office in Southwark. Basement flooding in the building's recent history had not been fully explained, and the tenant wanted to understand drainage risk before committing to the lease.

We identified a partially collapsed section of the surface water drain that served the property's courtyard, combined with an incorrect connection that had diverted surface water into the foul sewer. During heavy rain events, the combined sewer surcharge level exceeded the invert level of the connection, causing backflow into the courtyard drain. Our report gave the tenant the information they needed to require the landlord to rectify both defects as a condition of the lease.