The goal of the detailed evaluation program is to gain a thorough understanding of the existing conditions with an evaluation of the maximum expected service life of each roofing system. As facilities sometimes have various roofing sections and systems, the detailed evaluation will incorporate several testing procedures.
Historical Assessment
The first step in the evaluation process is to conduct an assessment of the roofing system's original design and construction features and to identify the repair and maintenance history. This initial phase in the project forms a data base which ensures that all relevant factors are considered in making roofing evaluations and recommendations. By questioning knowledgeable site personnel, valuable insights can be gained. In particular, we must determine if there were special criteria which influenced the original design, such as heavy trafficking or corrosive chemicals in the atmosphere which could cause premature failure. The historical assessment seeks to gain information about the frequency of leaks and how the client detects, diagnoses, and repairs roofing failures. This phase determines if any routine form of preventive maintenance program is in effect.
Visual Inspection
A detailed visual inspection is conducted at the site. The purpose of the visual inspection is to determine the general status of the roof, identify obvious failures, and collect information for the construction of as-built drawings.
Systematic Roofing Analysis' field service personnel conduct the visual inspections and document all potential problem areas in this report. SRA documents any problems noted during the visual inspection with an extensive photographic log. These pictures show some of the more significant problems identified during the survey.
Detailed Evaluation
As the historical assessment of the roofing system is completed, a detailed evaluation will be initiated. The main testing procedure will consist of a nuclear, moisture survey and detailed visual inspection. Roof core samples will be obtained for laboratory analysis.
The nuclear moisture survey provides an accurate, detailed and cost-effective method of evaluating existing roof moisture characteristics, prior to performing remedial procedures. Every square foot of the roof system will be analyzed, and all areas of failure, leaks or wet insulation will be located and marked directly on the roofing surface. The entire investigation will be conducted with portable equipment, and photographs of all failed areas will be provided for permanent records.
In conjunction with the nuclear moisture survey, a detailed visual inspection of each roof area and system will be conducted. All flashing components will be evaluated relating to integrity, service life, defects and remedial efforts required. All major defects will be marked on the roof for future reference.
The final result of SRA's evaluation will be a formal report which will include field data, detailed scale drawings of all areas, photographic documentation of field conditions, recommendations as to repair/replacement schedules, and cost estimates for a five-year maintenance program.
Nuclear Moisture Evaluation
A nuclear moisture evaluation is conducted to determine the moisture content in the roofing system using a Troxler Model No. 32l6 Moisture Meter. The nuclear gauge detects hydrogen through the use of a weak radiation source. High speed neutrons with the same mass as hydrogen atoms are emitted into the area being examined. Some neutrons collide with the hydrogen atoms, slowing them down and bouncing them back to the instrument where they are counted for fixed intervals.
The nuclear gauge indicates the moisture in an area approximately twenty-six inches square and eight inches deep. Since the gauge analyzes only a small area at a time, a sampling plan is designed to thoroughly represent the entire roofing system. This normally means establishing a grid on the roof and measuring moisture content at each grid point. This procedure permits the detection of trapped moisture not only in the roofing membrane, but in the insulation system below. The gauge is first calibrated to determine the nuclear count for a dry section of roof. Then, readings above this base level can be interpreted as slightly damp to wet, based solely on the gauge's moisture count.
SRA provides a drawing of your facility showing a grid at ten foot intervals. At each interval, the number indicates the moisture content in the roof system. See example of SRA's roof evaluation drawing.
Delmhorst Moisture Probe
The Delmhorst moisture probe is designed to test moisture levels in plasterbuilding materials and roof insulation through qualitative comparative readings. The moisture content of the roof material is read through two electrical probes that are inserted into the roof insulation. The concept being dry insulations are poor conductors of electricity and wet insulations are good conductors, thus sending the reading to the probe. The process of using the Delmhorst probe is time consuming, in that each reading on the roof system requires punctures in the roof membrane on a grid method and appropriate repair patches must be installed to maintain the watertight integrity of the roof materials.
Infrared Evaluation
Thermographic Infrared Roof surveys work on the principal that different materials in the roof system composition have different thermal mass. In the daytime the sun heats the roof substrate. After the sun sets, the roof begins to cool. If there is moisture trapped in the roof substrate, the insulation will become “wet”. The “wet” insulation has a higher thermal mass than the surrounding dry roof substrate. As a result of this difference, the wet areas will maintain heat energy longer than other areas providing the infrared camera with a clear picture of the moisture area.
Thermal infrared inspections are a non- destructive testing procedure. The infrared camera allows a professional thermographer to scan large areas of roof from a distance. Traditional roof inspection methods require a grid type contact search, normally referred to as a Nuclear scan.
Infrared moisture surveys can only be performed during the nighttime hours and rely on specific weather conditions. In addition, infrared cannot be used as a nondestructive moisture testing procedure on ballasted or paver-surfaced roof systems.
The moisture survey concludes with the issuance of a formal report. Included in the report are scaled CAD drawings showing all areas of moisture laden insulation, infrared photographs with corresponding daytime photos, with description of deficiencies, recommendations for repair or replacement and construction cost estimates for recommended roof work. Also, core sampling is utilized to confirm the survey findings.
Photographic Evidence
SRA provides detailed color photographs of the roofing system and results of the visual assessment. The pictures allow maintenance, engineering, architectural and construction personnel to become familiar with the roofing system and the results of our visual inspection without the need to visit the site. SRA's Photo CD capabilities have provided our clients with precise descriptions of our evaluation and also has been useful in providing them with digital photographs. Each photograph will show items of concern with deficiencies in the roof system, and also a recommendation.
Recommendations
The culmination of SRA's roofing evaluation is a report summarizing our recommendations and findings. The recommendations address the most critical question of whether an existing system can be salvaged, recovered, or completely removed and replaced. Based on our experience and the results of our evaluation, Systematic Roofing Analysis has recommended a course of action which will result in the least costly approach to resolving the present roofing problems.
PREACQUISITION
A roof investigation is performed to evaluate the roof system and components to determine the service life prior to a client purchasing a property.
DESIGN SERVICES
The purpose of the design services package is to provide a comprehensive service including roof system selection, design, specification, contract documents and construction inspection.
Plans and Specifications
Upon completion of a roofing system evaluation, certain roofing sections may require remedial work, while others, require replacement in part or entirety. SRA will employ its experience in developing the least costly design alternatives and provide necessary technical design services.
On roof systems where remedial work is cost effective and the service life of the roof can be extended, we will provide detailed construction drawings and contract documents for bidding purposes. The information gathered during the roof system evaluation will be incorporated into the bid packages, so a detailed scope of work can be provided to prospective roofing contractors. SRA will develop Request For Proposals (RFP's) based on lump sum contracts.When the roof system on a particular building area requires replacement, Systematic Roofing Analysis will prepare reroofing specifications, detailed construction drawings and contract documents. Our specification writers and project managers will conduct a thorough analysis of the available roofing systems, in order to determine the most compatible system type which meets with the Owner's criteria and budgetary requirements. Particular attention will be given to design parameters such as:
1. Roof size and layout characteristics
2. Roof expansion and contraction characteristics
3. Roof deck and structural load capability
4. Roof slope and drainage system characteristics
5. Perimeter edge and flashing details
6. Roof top equipment, supports and through roof penetrations
7. Existing system retrofitting feasibility
8. Roof traffic patterns
9. Contaminant discharges or spills on the roof
10. Contaminant exposure from adjacent plants or facilities
11. Regional climatic conditions
12. Installation methods and logistics
13. Future maintenance requirements
14. Future facility expansion considerations
15. Budgetary considerations
Once all the required performance criteria have been evaluated, defined, and coordinated, the roofing system design can be tailored to provide the best system for the project.
Bidding and Negotiating Phase
Careful planning, timely bidding, and the method of bidding are important factors for cost savings in reroofing projects. The method of bidding is a crucial factor when deciding to use an individual bidder versus competitive bidding. Using a union roofer versus a non- union roofer will, also, have an impact on the bid price. Typically, during the first and second quarters of a fiscal year, the contractors are more aggressive in their pricing. Therefore, when grouping and preparing the plans and specifications for projects in similar geographical areas, all projects can be out for bid prior to the end of the second quarter of the fiscal year. SRA recommends using competitive bid with at least five bidders.
Methods of Bidding
The methods of bidding is a crucial factor when when deciding to use an individual bidder versus competitive bidding. Notice how the Group bid in the graph below indicates each job's bid was lower than that of an individual bid. Building owners would greatly benefit from a group bid, than a single contractor's bid.
INSTALLATION QUALITY ASSURANCE
The goal of the construction inspection program is to provide on-site, quality assurance services and represent the Owner in any and all field-related activities. These services will ensure that the roofing contractor properly implements the technical design in an accurate and reliable manner.
During the remedial repairs or reroofing construction, Systematic Roofing Analysis will provide on-site quality control inspectors, as well as project management staffing. We will ensure that all roofing work is conducted in compliance with project plans and specifications. SRA on-site inspectors maintain daily, written reports and obtain photographic documentation as work progresses. If necessary, we are equipped and experienced in performing all ASTM testing and roof core sample procedures.
The scope of services SRA provides under the construction inspection services heading are as follows:
A. Installation Stage:
1. Review, monitor and report progress of Roofing Contractor's Construction Schedule.
2. Review vapor retarder, insulation, accessory metal work, and roof membrane and flashing materials for compliance with project contract documents and approved submittals.
3. Process roof samples per specification requirements (if applicable).
4. Monitor and report unnecessary or damaging traffic over new roof installation.
5. Document deficiencies (if any) in the new roof installation and ensure the roofing system is installed in accordance with accepted roofing practice.
6. Document noncompliance by Roofing Contractor, using photographs.
7. Prepare Quality Control Reports which will provide a written summary of work performed, area worked, test results, and other pertinent information. Photographs and roof diagram graphics will support these written reports.
B. Post Installation Stage:
1. Report repair of all damaged or deficient roof areas.
2. Assemble project data for Owner's file.
3. Issue Quality Control punch list based upon visual inspection. (Infrared and nuclear evaluations are available at additional cost.)
The end result of a properly implemented Construction Inspection program will be roofing repairs that permanently correct a failed area and contribute to additional service life of the roofing system. Under roof replacement, all construction work will be performed within the contract specifications and will not have potential failures built into the system. Adequate construction inspection will add years to the roof's service life, and thus reduce the annual prorated roofing cost.
PREVENTIVE MAINTENANCE
SRA recommends formulating a preventive maintenance program for all existing and new roof systems. The main purpose of preventive maintenance programs is to establish a simple checklist designed to be utilized by internal maintenance personnel as a reference and yearly inspection of your roof systems. SRA would provide this form listing all items on the roof system which require inspection. These areas will consist of interior and perimeter flashings, rooftop equipment and penetrations through the roof system. Maintenance inspections include inspection and cleaning of all drains, which should be performed twice yearly, in the fall and spring. It should be noted, that a number of items on your roof may not be subject to warranty coverage, such as caulking, terminations, counterflashing, contaminant discharges onto the roof, ponding water and wind damage due to high wind or storm activity.
A well detailed preventive maintenance program will detect potential failures developing within the roof system before system failure occurs. When moisture penetrates the roof system, if detected in an early stage, repairs can be conducted under the warranty at no cost to the Owner. If major failures remain undetected, total system failure can occur, and most manufacturer's warranties indicate yearly inspections should be conducted. A comprehensive preventive maintenance program will add years of cost-effective service life to your roof system, as well as documentation of any potential problems developing within your system that may need immediate attention and remedial repair.
SRA would be pleased to train your internal personnel to conduct these inspections. This is a simple, four to eight hour presentation which can be conducted at your facility to identify and provide review of the checklist, as well as a rooftop inspection identifying the pertinent items which may require twice yearly inspection.
COST ANALYSIS/BENEFITS
Long Term Budgeting
Over the years, SRA has developed roof programs for clients with buildings in a close geographic location. This program was established so that the roof systems could be evaluated for proper prioritization followed by the execution of a design package including first quarter bidding to achieve the most cost-effective savings during a fiscal year. Typically, the process includes building roof systems that have been visually inspected by the client's operations personnel to assess existing conditions and problems. On a yearly basis, a list of projects is generated for investigation by SRA, which we normally conduct in the second and third quarter of each year. After evaluating the roof systems, SRA determines if they are serviceable or will require replacement. A prioritized list is generated with cost estimates for the roof replacement activity, so that long-term budgeting can be achieved. Once a list of buildings has been established for roof replacement, SRA provides budget estimates for design and specification development.By executing this first phase, evaluation in the second and third quarters, roof systems can be prioritized allowing enough time for careful planning, so that roof replacements can be combined in the same geographical locations, enabling contractors to look at more than one project. This achieves cost savings in the bidding process, as well as prebid meetings, preconstruction meetings and contract award. Additionally, construction inspections and on-site quality control, which should be implemented during the roof replacement project can be scheduled in advance, to achieve further savings.
Benefits
There are numerous benefits to an effective roof management system. A roof management program in place can prolong the service life of a roof system. A roof system with no program currently in place will not be as effective, and you can expect the service life of the roof system to be diminished dramatically. The following are just some benefits to an effective roof management system:
Locate and stop existing leaks to prevent additional damage.