In the commercial roofing field, there is a great interest in green roofs, LEED, reflectivity, emissivity, photovoltaics, carbon footprints, sustainability, recyclables, and landfill capacity. With petroleum reaching $100 per barrel, energy conservation and efficient building design are certainly in the forefront of our minds; however, in the flood of articles being published, there is very little on what the individual property owner or building manager can do (short of starting over with a new building design or adding thermal insulation at the time of reroofing or recover).
Inspecting and Maintaining What We Have
Many previous issues of Roofing News have focused on the benefits of inspecting existing roof systems periodically. For buildings that are heated in the winter and cooled in the summer, the in-situ thermal resistance of the roof insulation is a huge energy saver – not the designed R-value, but the in-place insulation value. This can differ considerably from what the intended R- or U-value was due to air leakage, wet insulation from either condensation or roof leaks, or poor installation practices.
Infrared surveys have proven worthwhile in detecting air leakage and wet insulation, but are not effective with ballasted roofs, vegetated roofs, protected roof membranes, and some instances of cellular thermal insulation. When wet thermal insulation is detected, it can be very cost effective to do partial roof replacement, returning the roof system to its designed thermal performance as well as its intended life. Nuclear and capacitance devices can also be used by an experienced equipment operator, but only if the operator is familiar with roofing and verifies the instruments’ readings. The payback on scheduled surveys can be excellent, especially if one considers the shortened life of a leaking roof, the potential loss of decking, wood blocking, and potential business interruption. The same can be said of regularly scheduled visual inspections.
Achieving a Quality Roof System
Even when a roof system has been well designed and has quality materials specified, sometimes the result is less than hoped for. The December 2007 newsletter on ASTM Intl. discussed how ASTM goes about developing a new product specification or recommended practice; however, ASTM sometimes goes further in the roofing and waterproofing area, especially when assisted by RCI Inc. (the Raleigh, NC-based Institute of Roofing, Waterproofing, and Building Envelope Professionals). This is the case with ASTM D7186, Standard Practice for Quality Assurance Observation of Roof Construction and Repair. This document was developed to a great extent by members of RCI Inc., but published through ASTM’s consensus process. Highlights of the joint ASTM/RCI specification follow. (The entire D7186 specification is available for purchase on ASTM’s website.)
Scope. This practice covers procedures for performing visual monitoring of roofing construction in order to:
- Establish guidelines for quality assurance observation practices.
- Define the role and responsibilities of the quality assurance observer.
This practice pertains to daily, full-time quality assurance observation of roofing projects. This standard is applicable to new construction or reroofing projects involving the installation of a new roof system, the removal of existing roofing and installation of a new roof system, or recovering an existing roof. It is also applicable to roofing projects involving repairs or scheduled maintenance to an existing roof.
This practice contains the following information:
- Objectives of the quality assurance process.
- The responsibilities and qualifications of the individual(s) involved in the observations of the roof construction or repair.
- Identification and use of the basic tools or equipment required for the visual roof observation process.
- Monitoring, recording, and reporting procedures.
(This standard does not pertain to quality control processes or techniques performed by persons or entities representing or under contract to the roofing contractor. The quality control process is separate and distinct from the quality assurance observation process.)
Significance and Use.
- Quality assurance observation of roofing projects is an important process for determining if the removal, installation, repair, or maintenance of roofing materials or systems follows the scope and intent of the Contract Documents, and are installed and executed in accordance with accepted roofing practices and the Contract Documents.
- This practice is applied to full-time quality assurance observation of roofing projects involving the removal, construction, and repair and maintenance of low- and steep-slope roof systems and roofing-related accessories.
- This practice establishes the role and responsibilities of those performing quality assurance observation, and includes qualifications of the quality assurance observer, as well as procedures for observation and documentation during the roof construction or repair process.
The Role of the Quality Assurance Observer (QAO)
The presence of, or opinions expressed by, the QAO do not relieve the contractor, manufacturer, or other responsible party of his/her contractual requirements. The information provided by the QAO is for the benefit of the owner (or other client); no warranty of roof performance, expressed or implied, is offered, neither should it be inferred based on the quality assurance observations.
The QAO’s function is to provide onsite observation and reporting of the roof construction process in a clear, accurate, and objective manner, using procedures indicated in this standard. The QAO shall observe and record:
- The general conditions of the jobsite, roof areas under construction, and materials used in the construction process and their storage.
- Pre-existing property damages, or property or material damages that occur during the roof construction process.
- The condition of the substrate and substrate preparation, repair, or replacement procedures.
- The installation and attachment of any base sheets, including the type of fastener or adhesive used, the fastening pattern, and spacing.
- The installation and attachment of any vapor retarders or air barriers, including the type of fastener or adhesive used, the fastening pattern, and spacing.
- The installation and attachment of the insulation layer(s), recover or coverboard materials, including the type of fastener or adhesive used, the fastening pattern, and spacing.
- The installation and attachment of the roof covering or repair materials which comprise the finished roof system, including the type of fastener or adhesive used, the fastening pattern and spacing, as well as specific material quantities, temperatures, and measurements appropriate to the type of roof system under construction.
- The installation and detailing of the roof system flashings at perimeter and roof penetration locations.
- The installation and detailing of the sheet metal roofing accessories such as, but not limited to counterflashings, coping caps, joint covers, and edge and fascia metals.
- The installation of roof surfacings or coatings.
- The installation of temporary weather seals at the end of the workday or prior to inclement weather.
- The installation of any other roof components specified in the project specifications.
- The weather conditions that occur during the roof assembly installation.
- The crew size and foreman, and type of work being performed on a given day.
- All visitors to the site roof and their length of stay.
Qualifications of the Quality Assurance Observer.
Significance of qualifications:
- It is necessary that the person(s) performing quality observation of the construction process understand the project specifications and the specified roof system. Knowledge of industry-accepted good roofing practices is critical to the success of the quality assurance observation process.
- A record of experience and training shall be maintained by the QAO and submitted to the project file. (A Record of Training & Experience sample form is available for optional use in ASTM D7186.)
- A thorough understanding of the contract documents, specifically the project specifications, construction detail drawings, pre-bid and pre-construction conference minutes, and any addenda to the roofing specifications is required.
- A thorough understanding of the type of roof system specified, including general knowledge of the manufacturer’s requirements, is required.
Technical qualifications of the QAO can be achieved by:
- Completion of specialized training or certification in Quality Assurance Observation. The training or certification program shall be specific to roofing quality assurance observation and shall be administered by an industry-recognized organization.
- Completion of a roof system application program provided by the roof system manufacturer specified.
Required Project Documents. A copy of the following project documents shall be maintained onsite by the QAO and updated as necessary:
- The contract documents, including scope of work, specifications, roof plan, construction detail drawings, addenda, and modifications.
- The pre-bid and pre-construction conference minutes, and project meeting minutes.
- Stamped material submittals.
- The contractor’s original construction schedule and any revisions.
- Appropriate manufacturer’s literature containing roof system or material application requirements.
- Construction change directives, change orders, and any field orders.
- Written and photographic documentation prepared by the QAO.
- Other pertinent project correspondence.
- An emergency contact list for all pertinent project personnel.
Observation and Recording Procedures. Documentationshall include both a written and photographic record for historical file purposes and shall be made available to all parties involved in the roofing project. Project documentation may begin at the pre-construction conference or earlier and shall be continuous for the duration of the roofing project. Written documentation shall be clear and concise, and present an accurate, objective account of the roof construction project. Reports shall accurately describe the sequence of events, installation methods, workmanship by the contractor, and problems encountered and corrective actions taken.