Going by the book
The latest edition of The Drain Repair Book is a best-practice guide devised by insurers for contractors working in the public and private sectors. Iain Naismith of the WRc group outlines the updates
First launched in 1993 and updated in 2005, the second edition of The Drain Repair Book (DRB2) has applications beyond insurance-funded repairs into the public sector. This applies both to local government in managing repairs under their public health duties and for sewerage undertakers preparing for the proposed transfer of private sewers and lateral drains to their ownership.
So what does this best practice devised by the insurers involve? Why did they need it? And what developments necessitated a second edition? There are essentially two elements to insurance industry best practice. The first is in claims handling for insurers. The second is technical best practice for drain inspection and repair to be followed by contractors, insurers and adjusters. DRB2 addresses the latter and is built around the following three principles:
- There must be accurate identification of drain condition and assessment of its serviceability
- The need for a repair must be correctly identified
- If a repair is required, the appropriate repair technique and scale of repair must be selected to make the drain serviceable
The insurers' requirement for best practice derives partly from their need to achieve cost-effective repairs on each individual claim and partly from the need to collaborate among themselves over shared claims deriving from failing private sewers.
Royal and SunAlliance began the best practice process when it concluded that the private drainage market was fragmented, with inconsistent quality, no minimum standards and little regulation. It developed a two-part in-house manual covering claims handling and technical repairs, commissioning the latter from WRc because of its expertise in public sewer renovation and authorship of The Sewer Rehabilitation Manual and The Manual for Sewer Condition Classification.
Having set its own house in order, Royal and SunAlliance decided to spread best practice across the industry and formed the Drainage Forum. What concerned the insurers was a high and increasing drainage spend, an increasing problem of failing pitch fibre pipes, lack of control of claims, a lack of technical drainage and the absence of common best practice for the drainage repair industry. Royal and SunAlliance offered its Technical Manual as the basis for an industry document. The Drainage Forum accepted and commissioned WRc to prepare the Drain Repair Book with the support of top-performing drainage contractors. The guidance is divided into three parts:
Part 1 Technical guidance for drain investigation and repair
Part 2 Specification for repair work
Part 3 Materials specification for cured in Place (CIPP) systems
This Drain Repair Book proved to be an important vehicle for achieving the Drainage Forum's aims of:
- Establishing best practice
- Educating insurers and their investigators
- Encouraging insurer co-operation on shared claims
- Establishing a protocol for insurers, investigators and contractors for handling shared claims
- Creating a Claims Agreement for the insurance industry on drainage
The benefits for drain repair specialist
companies using the best practice ensures technical quality and the appropriateness of the solution offered is considered in awarding contracts. It provides professional credibility and encourages confidence from property owners and insurers. For insurers, best practice removes uncertainty, ensures standards and provides more control
over claims spend. For investigators it improves understanding of technical issues, assists them in technical dispute resolution, removes doubt over best methods and enables quicker claim settlement.
WRc has provided training to support its adoption through a two-day Essentials for Managing Drain Repair course. The feedback proved valuable in identifying the need for a second edition.
The UK Drainage Network, formed by Royal and SunAlliance contractors at the time of the original book launch, has stated that following the DRB2 guidance on surveys, job scoping, and repairs has allowed it to deliver proven cost savings of 40-50% on typical drainage claim costs.
Application of best practice
The Drain Repair Book has always been seen as a living document that would evolve as uptake progressed. The second edition, published in November 2005, includes two new sections - a glossary to provide clarity in the definition of commonly used terms and a chapter on septic tanks. Septic tanks are often poorly maintained so the book now sets out responsibilities for routine inspection and regular maintenance, the investigation procedures for pipework, tank and drainage field and decisions on repair.
Enhancements include a new general investigation category alongside two existing categories of reactive (emergency) and subsidence investigations. More guidance has been necessary on determining serviceability following root ingress and for pitch fibre pipe.
Modifications were needed to accommodate new building regulations and the new rules on work in streets. Assessing responsibility for the drain has been updated to reflect new lateral drains becoming adoptable from May 2004, and a new section on ownership in Scotland has been added. The section on blockage removal now stresses the priorities as being to quickly restore flow, but also to remove debris and avoid damage to pipework in the process, with specific reference to the new second edition of the Sewer Jetting Code of Practice. The second edition now includes patch (localised) repair, reaming and pipebursting/re-rounding. Following a repair a water drop test/air test to detect leakage is recommended. However, The Drain Repair Book does not include the water pressure test cited in building regulations for new lay drainage since using high pressures on old joints could create leaks. Part 2 sets out basic separate requirements for patch repair and CIPP and the section on Excavation and replacement now includes details of bedding and side-fill requirements.
Part 3 also contains clauses on claiming compliance with the manual for materials specification for CIPP and patch repair Systems. It should be noted that The Drain Repair Book details performance specifications, not methods, and therefore applies to the range of lining solutions: ambient cure, hot cure, polyesther, epoxy and silicates.
Now the industry has a technical best-practice manual, contractors can compete
on an even footing.