Guidance Note on the Avoidance of Water Damage on Construction Sites

Transcription

1 Guidance Note on the Avoidance of Water Damage on Construction Sites Introduction Over recent years the incidence and magnitude of water damage claims in the construction industry, arising from internal water services, has been on the increase. The reasons for this increase are many and varied and the causes not always simple to tackle. Unfortunately, to date, the industry has failed to attempt any co-ordinated response to address the problem. The purpose of this document is to outline some of the ways in which the industry can attempt to tackle the root causes of the problem and also to suggest ways in which organisations and individuals can mitigate the effects of an incident should a loss occur. Contents 1.0 Project Management 2.0 Sub-Contractor Appointment 3.0 Quality Control 4.0 Mitigation Appendix: Risk Assessment Template This Guidance Note is intended for Projects during their Design & Construction Stage and also for On-going Construction Projects. It is acknowledged that whilst on-going projects would not necessarily have the immediate benefit of all the Risk Management measures proposed, it should nevertheless be used as a practical guide and a Best Practice reference point as the project develops. The guide is not intended to be applied to the construction of individual dwellings (though some of the recommendations may be applicable). 3rd Edition 1 4 th May 2010

2 1.0 Project Management 1.1 The Design Team should be tasked with designing out features that are known to exacerbate water damage losses and include those that may mitigate a loss should an escape of water occur. Examples of unfavourable features include: combined service risers inappropriate or concealed pipework routes positioning of water tanks open risers porous cabling electrical cables laid directly onto floor slabs. The design should allow for: additional isolation valves; riser upstands; full and easy access to pipes; and temporary drainage points from the floor plates to help mitigate the effects of escaped water. 1.2 The selection of the water distribution system(s) should be based on a comprehensive risk assessment which should take into account the following factors: the loss history associated with various types of plumbing system the building occupancy the building s susceptibility to water damage (type and quality of finishing to be employed) the height of the building the presence of drainage points the sub-contractor appointment process design input & supervision testing/certification procedures the presence (or absence) of mitigation features (e.g. water management devices, bunding and leak detection) the presence of in-built system safeguards. the potential for damage being caused by pressure surges If the design and system selection is already complete then the adoption of other measures detailed in this document remain valid for effective risk control and mitigation. 1.3 The Principal Contractor or Employer should be responsible for the management of the water damage risk and it is strongly recommended that they nominate an experienced individual to accept responsibility for managing / overseeing this exposure. This individual should ensure: the selection and appointment of skilled sub-contractors and labour (in accordance with section 2) incorporation of written procedures (with respect to installation, testing and commissioning) into contractual terms verification of installation standards and adherence to codes as detailed below that independent site checks and quality control are carried out pressure testing and commissioning procedures are completed full certification of work with audited records verifying compliance with all requirements written quality systems and document control are maintained 1.4 A Water Management Plan should be drawn up detailing responsibilities, procedures and specific actions required to manage all the aspects detailed within this document (both pre and post loss). 1.5 The works should be phased to reduce the likelihood (and severity) of damage from burst pipes or weather-related incidents. Roof and cladding should, ideally, be complete and the envelope made water-tight before internal works of any description are carried out. Where the phasing of the 3rd Edition 2 4 th May 2010

3 works makes this unachievable, the nature and extent of the fit-out works undertaken prior to weather tightness should be subject to a damage risk assessment. 1.6 Permanent drainage should be installed early with full functionality or, alternatively, specific measures put in place to manage the discharge of water from the building. These measures should be detailed in the Water Management Plan. 1.7 Ensure bunding is complete and drainage from plant rooms connected before tanks are filled. Aim to achieve early commissioning of sump pump alarms, leak detection, water management devices and also enabling of the facility to monitor these (often the Building Management System). Any alert system should be routinely checked or remotely monitored. 1.8 Pipework and valves to be identified and labelled as works proceed, not at completion of the project. Valve location and function should be included in the emergency procedures. When working on existing systems, the location and function of all valves should be established, and effectively communicated, prior to work commencing. The template appended to this document can be used to facilitate the risk assessment process and can also be used to form the basis of the Water Management Plan 3rd Edition 3 4 th May 2010

4 2.0 Sub-Contractor Appointment 2.1 Only qualified plumbers with appropriate skill sets should be permitted to work on water distribution systems. It is strongly recommended that persons employed to work upon water distribution systems have, as a minimum, a NVQ level 3 (or equivalent) and are affiliated to an industry body such as the IPHE or IP (see below). Apprentices and trainees should be under the direct supervision of qualified plumbers. Unqualified operatives should never be engaged to work on water services unsupervised. 2.2 Where new systems are employed using different techniques or bespoke machinery, all operatives should be fully trained by the manufacturer supplying the system and training records kept to verify this training has been completed. As a minimum, operatives should have received verified training on the proposed system within the last 12 months. 2.3 The Principal Contractor or Employer should ensure the on-site inspection and certification of the trade contractor s work throughout the process. This task can be delegated to a suitably qualified, independent third party. 2.4 Individuals engaged to work on plumbing installations should be affiliated to an industry body such as the Institute of Plumbing and Heating Engineers (IPHE) or the Institute of Plumbing (IP). 2.5 Plumbing and HV companies should be members of recognised industry associations such as the Association of Plumbing and Heating Contractors (APHC) or the Heating and Ventilation Contractors Association (HVCA). 2.6 Membership of Approved Contractor Schemes (ACS) is a further indication of quality e.g. the IPHE Approved Contractor Scheme and the Water Industry Approval Scheme (WIAPS). Similar schemes are also run by some of the larger Water Authorities and are generally considered to be of equal status. 2.7 All operatives should be required to produce evidence of association membership at induction. Records should be maintained by the Principal Contractor. 3rd Edition 4 4 th May 2010

5 3.0 Quality Control 3.1 The Principal Contractor or Employer should implement a procedure for independent certification of work carried out throughout the installation, testing and commissioning. This procedure may be undertaken by the Principal Contractor and should be documented and auditable. Self-certification by the installing trade contractor is not acceptable. 3.2 All contractors should be required to work to industry recognised codes which should be clearly defined in all work specifications and contractual documents. The main applicable documents are: Water Supply (Water Fittings) Regulations 2000; BS6700:2006 Design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages : specification; HVCA Good Practice Guides; and CIBSE (Chartered Institute of Building Services Engineers) standards. 3.3 Ensure strict compliance with design guidelines and manufacturer s installation manuals. Any operatives working on a system should have received on-site training by the system supplier. Training records should be maintained by the Principal Contractor. No matter what the nature of the system, installation work must only be carried out by qualified, trained personnel or supervised apprentices. 3.4 All joints should be subject to a visual inspection as part of commissioning and for a period not less than 2 weeks thereafter. In areas where access is not possible for visual inspection, consideration should be given to leak detection at strategic points e.g. at the feet of service risers. This should form part of a formal, documented procedure which should also include testing of the pipework, commissioning and certification. 3.5 All pipework should be subjected to a clearly defined Pressure Testing regime in accordance with the manufacturer s guidelines (which will be specific to the system employed). Failure to test an installation to the correct pressure for the required duration may nullify the manufacturer s warranty (this applies to pressures and duration being too low as well as too high). 3.6 In most circumstances, unless otherwise directed by the system supplier, pipework should be subject to an initial air test followed by sectional hydraulic testing at a minimum of 1.5 times the working pressure for a minimum duration of 2 hours. Account needs to be taken of the daily variation in mains pressures when determining the normal working pressures. 3.7 Pressure testing should be witnessed by the Principal Contractor or independent third party, such as a commissioning manager, and should never be conducted unattended. 3.8 All sections of pipework should be certified to have met the test standard and certificates should be issued for each section of pipework tested. The Principal Contractor should be responsible for auditing this paperwork. 3.9 Industry-recognised guidance documents should be regarded as the default position if manufacturer s guidance is not forthcoming e.g. The Guide to Good Practice Site Pressure Testing of Pipework produced by the HVCA and also BS Following sectional testing, full pressure tests should be carried out on systems in their entirety, including all equipment and fittings at their working pressure, in line with equipment supplier s guidelines. A minimum commissioning period of 8 hours is recommended which should be attended for its full duration by an operative familiar with the installation. 3rd Edition 5 4 th May 2010

6 3.11 It is advised that water management devices are installed with audible signalling to provide a warning of failure in any part of the system There should be a full audit trail of all components used, the testing regime, commissioning procedures and approval certificates The Water Authority will inspect all new-builds and issue a certificate of compliance which should be made available for third party audit. This certificate is not a guarantee of workmanship, only confirmation that appropriate fittings have been used in the installation. 3rd Edition 6 4 th May 2010

7 4.0 Mitigation 4.1 Switch off temporary water supply(s) outside working hours. It is recommended that a master valve is located in an accessible location and a designated person nominated to perform the task. Where a boosted supply is installed and is operational, some thought should be given to whether it is possible to isolate these without causing damage to the installation (consideration needs to be given to the effects of thrust pressure when these are turned back on). 4.2 Install a water management device on the incoming riser and programme it to shut down the water supply when water flows exceed pre-determined parameters; these parameters should be set in relation to normal water usage. The device should be set to shut off water supplies outside working hours when very small flows are detected. The device should have the facility to monitor normal water usage over a time period so it can then be programmed to allow water to be shut-off at a very precise, pre-determined flow rate outside of the normal usage parameters. 4.3 The water management device should have an integral battery back-up to ensure that it is effective during the testing and commissioning stage when power is often isolated for long periods. On unmanned sites such a device should be configured for remote monitoring. 4.4 Dependent upon the configuration of the HVAC system, consideration should also be given to installing water management devices on header tanks of enclosed systems. In a residential development, if fitted to individual flats, they can provide protection for finished units prior to occupation. 4.5 Install and commission leak detection, with temporary alarms, in areas such as bunds, the bottoms of risers, equipment rooms, around AC units and in vulnerable cable trays. In an unattended building, alarms should be linked to pagers, or other form of remote monitoring, and an emergency response procedure put in place. 4.6 Security guards, where present, should be trained to provide an early emergency response and to manually shut down systems, where appropriate. Un-manned sites should have personnel cover for emergency out of hours call out to respond to remote monitoring of leak and flow detection. On larger, high value or complex projects consideration should be given to a full time attendance by an engineer with intimate knowledge of the system. 4.7 Guards duties should be extended to routine patrols to check for escape of water where wet services are live. They should be trained in how to respond when discovering an incident. Similar emergency response duties to be allocated to nominated individuals where security is not employed or not present during the day. 4.8 Emergency procedures should be clearly defined within the Water Management Plan including a call out list and knowledge of, and access to, isolation valves. Spill kits and pumps should be made available. A method statement for water isolation to be produced and updated during construction works so that is clear how isolation can be achieved. This isolation procedure should be tested at intervals throughout the construction process. 4.9 Within the Water Management Plan establish the means for bringing in, handling and discharging temporary and permanent water supplies in the buildings under construction. This should include designated water discharge points/routes, and should include supply/discharge of water from roof drainage systems, sprinklers, HVAC systems and temporary welfare & accommodation facilities, where set up inside the building. 3rd Edition 7 4 th May 2010

8 4.10 Temporary rising mains for use of wet trades should be tightly controlled with lockable discharge points. Water butts can be used to ensure only limited quantities of water are available inside the building. Externally routed temporary pipes should be insulated and/or heated to prevent freezing Wherever possible, a permanent supply should be installed in preference to a less reliable temporary mains e.g. through utilising a fire fighting water supply. Temporary water discharge pipes must not be placed in electrical (or other water-susceptible) service risers All incidents of water escape or water damage should be fully investigated and documented. This information should be shared with the Insurance Company and, where possible, remedial measures put in place to prevent a reoccurrence. This guidance is endorsed by the membership of the UK CAR Underwriters Group and the Construction Insurance Risk Engineers Group (CIREG) The UK CAR Underwriters Group CIREG ACE Endurance RSA ACE Allianz Cornhill Eng FM Global SCOR Allianz Global Corporate Allianz Global Corporate General Re Swiss Re Chubb Aspen Re HD- Gerling Tokio Marine Global Axa Corporate Solutions Houston Casualty WR Berkley Beazley Liberty XL Insurance Catlin Mitsui Sumitomo Zurich Global HDI-Gerling Liberty Mitig8 Mitsui Sumitomo Chaucer Chubb Munich Re Norwich Union Risk Engineering Solutions Zurich Global UK CAR Underwriters Group/CIREG Water Damage Co-ordinator and Technical Contact - M Redding Mitsui Sumitomo mredding@msilm.com or contact other member of the sub-committee I Lushington Allianz Global Ian.Lushington@Allianzglobalrisks.co.uk C Rose Beazley Colin.Rose@beazley.com D Huggins Mitsui Sumitomo dhuggins@msilm.com C Jones Zurich Global caroline.z.jones@zurich.com 3rd Edition issued on the 4 th May 2010 Disclaimer The guidance in this document is considered best practice loss control advice. Adoption of the provisions contained herein does not imply compliance with industry / statutory codes or guidelines nor does it guarantee that water related losses will not occur. 3rd Edition 8 4 th May 2010

9 Appendix: Risk Assessment Template Project Address Principal Contractor Plan Owner Date of Plan Next Revision Water Damage Risk Assessment Aspect No. Hazard Mitigation CIREG reference Owner 1. Design 1.1 No consideration has been given to designing-out features likely to increase the likelihood of damage or exacerbate the extent of damage should an incident occur 1.2 The selection of materials and systems is not subject to a full risk assessment taking into account the nature, height and future use of the building Temporary Supplies 2.1 The temporary supply is brought into the building without due consideration of how water will be safely discharged from the structure without damaging any building elements 2.2 The temporary supply is left live when the building is unattended 4.1; 4.9: 4.10; ; 4.6; 4.7 3rd Edition 9 4 th May 2010

10 2.4 No consideration is given as to how a leak will be detected and water flow isolated should the temporary distribution system fail / leak / burst 1.7; Section 4 3. Permanent Services 3.1 Lack of supervision, control and auditing by Principal Contractor or his appointed representative 1.3; 2.3; 3.1; There are no recognised or evident procedures for ensuring the quality of the installation work and adherence to the appropriate codes and standards 2.3; Section There are no recognised or evident procedures for ensuring the robustness of the pressure testing regime Section There are no recognised or evident procedures for ensuring the safe commissioning of the water services Section The selection of water services is not subject to a risk assessment by the mechanical services engineer The mechanical services contractor lacks the appropriate expertise to install the selected water distribution services (domestic, heating and air conditioning) Section New / innovative plumbing system to be employed with insufficient training for those involved in installation Tanks and pipework are to be filled prior to the completion of permanent bunding or drainage or the commissioning of leak detection / BMS monitoring and control 1.7; 3.9 There is no audit trail to verify the safe installation, testing and commissioning of the installations nor the use of suitable components 1.3: 2.3: 3.1; 3.8; rd Edition 10 4 th May 2010

11 3.10 There is no means for detecting and isolating the water supplies / heating systems in the event of a burst pipe, tank or fitting 3.11 There is no means for safely discharging water from a building should a leak occur 1.7; 4.2 to ; Isolation valves and pipework runs are not identified and labelled to allow the swift isolation of failed services Weather-related 4.1 The phasing of the works exposes vulnerable fixtures, fittings and finishes to wind-driven rain 1.5; 1.6; 4.7; There are no provisions (either temporary or permanent) for the removal of water from the roof of the building, to a safe place outside 1.5; 1.6; 4.7; Permanent drainage is not connected to allow for the removal of surface water or water being discharged from the incomplete building 1.5; 1.6; 4.7; 4.8 3rd Edition 11 4 th May 2010