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Loss Control & Risk Management

How and Why You Should Do a Pre-Construction Survey

Every year claims alleging property damage from construction operations are made against contractors. In order to protect their interests, contractors should consider pre-construction surveys when certain construction operations are planned. These include (but are not limited to):

  • Excavation and trenching.
  • Pile driving.
  • Use of heavy construction equipment close to other structures.
  • Dewatering operations.
  • Underpinning.
  • Blasting or demolition of a structure.

Conducting a Pre-Construction Site Survey

The first task usually undertaken for the site work is a pre-construction survey of the proposed site. The main purpose of a pre-construction survey is to develop a 'rough layout' of the site. This should include:

  • Location of the proposed structure and adjacent structures.
  • Location and condition of any existing structures or monuments, existing roads and parking lots to be retained.
  • All utility lines, gas lines, phone lines or cable lines near the proposed construction area.
  • All existing objects to be demolished.
  • Any existing trees or vegetation to be retained.

The planned construction activities and the degree of exposure to the surrounding area determine the need for and extent of the survey. The contractor should note that the actual field conditions are not always clearly identified and changes should be anticipated. Surveys may also identify potential problem areas that contractors should consider in pre-planning jobs. In the event that any structures or utilities adjacent to a construction project are alleged to have been damaged during construction work, another survey should be made at the completion of the work. This survey should be compared with the initial surveys to determine if any damage was caused by the contractor's operations.

A qualified independent consulting engineer should make pre-construction surveys. Written, accurate, dated reports should be kept for future reference. Insurance representatives or the contractor’s personnel should not make pre-construction surveys. In the event that a claim goes to court, the contractor's and insurance company's personnel may be considered biased witnesses, and their surveys may not be accepted as admissible evidence.

Pre-Construction Planning Surveys

The timing of a pre-construction survey is important. For example, if the contractor uses its own crews for an entire sewer-trenching project, including all blasting, a survey should be made before the work starts. Damage could be caused by the contractor's activities due to blasting vibrations or ground settlement.

The problem becomes more complex if other contractors are working in the same area. The pre-construction survey should be completed just prior to a contractor's beginning work on their portion of the project.

Area residents should be contacted and advised of the work to be done. This is good public relations. It should be explained to the area property owners that the pre-construction survey is designed primarily to detect any hazardous conditions or potential problems so the construction operations can be planned accordingly.

Adjacent property owners often will not tolerate frequent pre-construction surveys of their properties. In some instances, it may not be necessary to survey all adjacent properties; in others, all buildings up to three blocks away may have to be included. All buildings in poor condition in the affected area should be surveyed. Structures, such as religious institutions, museums, antique shops, and hospitals, should also be considered for pre-construction surveys, due to their high susceptibility to potential claims.

Guidelines for Making a Pre-Construction Survey

Once the contractor decides to have a pre-construction survey made, property owners involved should be contacted and advised of the nature of the work in an effort to obtain their cooperation. In most states, property owners do not have to permit surveys of their properties. However, refusal to have their property surveyed may be used to the contractor's advantage in the event of a subsequent damage claim.

Surveys of structures may include any or all of the following:

  • Written building condition reports by a registered professional engineer covering the condition of the foundations, exterior and interior walls, floors, ceilings, roof, chimney and other structural components. The reports should also cover the piping, heating and air conditioning units, hot water tanks, and other delicate machinery or equipment in the building.
  • Subterranean facilities, such as subways, tunnels, and electrical power vaults.
  • Photographs taken by an independent commercial photographer, under the direction of the professional engineer. The photos should be properly labeled, dated, and notarized to certify that they are accurate and true copies of conditions on the day they were taken. Black and white photographs are preferable to color, as they show more detail. Date stamp cameras help to provide documentation. Specific cracks or existing deterioration should be described in detail, measured and photographed.
  • Bench marks and/or survey points for vertical and horizontal references established by a licensed land surveyor to check for settlement and movement of building, roadways and shoring systems. Subsequent readings can be taken periodically by the contractor's survey crew to detect any ground movement. If unanticipated movement takes place, revised work procedures or corrective work should be considered immediately.
  • Videotaping of the project area and existing structures to help document conditions. An independent consultant as directed by the professional engineer should complete this. The videotape should be properly labeled and the date verified for future reference.
  • Ground water levels and water levels in adjacent wells should be recorded and checked periodically.
  • An independent qualified consultant should complete seismograph monitoring of surrounding vibration-producing operations (other than construction). The results should be recorded and kept on file. Blast logs and shot pattern records should also be compiled and kept on file.

To discover more ways to protect your business, check out the American Family Insurance Loss Control Resource Center.

COPYRIGHT ©2000, ISO Services, Inc.

The information contained in this publication was obtained from sources believed to be reliable. ISO Services, Inc., its companies and employees make no guarantee of results and assume no liability in connection with either the information herein contained or the safety suggestions herein made. Moreover, it cannot be assumed that every acceptable safety procedure is contained herein or that abnormal or unusual circumstances may not warrant or require further or additional procedure.

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Related Topics: Employee Safety , Protecting Your Business , Safety Programs