Roof moisture surveys, (TAS) 126-95, are reliable non-invasive tools to help pinpoint the scope of moisture infiltration. This survey, whether nuclear or infrared used in conjunction with the forensic roof analysis is a dependable tool used to initiate the course of action for either maintenance and/or replacement. Our easy to follow moisture survey report consists of a written description of the calibrated tools and methods in which the survey was performed. The findings and results are next described to identify the extent and scope of the moisture infiltration. Lastly, the survey graph is drawn in a ten foot grid scale with color coding to easily indicate the multiple ranges in areas of moisture infiltration. This vital tool will guide the corrective action to be recommended to direct and necessary repair.

The Troxler Nuclear Moisture Meter (Figure 1) is used to detect moisture as deep as 8" into the roofing system in roughly a ten foot by ten foot square. It will peer through all layers of insulation and can be used on all types of roofing systems. On projects where one roof has been installed over another, or on multi layered systems, a nuclear moisture survey is the only moisture detection method that will accurately locate moisture located the bottom layers of insulation installed to the deck. The meter detects moisture in the immediate area of the meter; consequently many readings must be taken over the entire roofing surface to insure that there are no moisture laden areas that go undetected.

Thermography is the use of an infrared imaging and measurement camera to "see" and "measure" thermal energy emitted from an object. Thermal, or infrared energy, is light that is not visible because its wavelength is too long to be detected by the human eye; it's the part of the electromagnetic spectrum that we perceive as heat.

Unlike visible light, in the infrared world, everything with a temperature above absolute zero emits heat. Even very cold objects, like ice cubes, emit infrared. The higher the object's temperature, the greater the IR radiation emitted. Infrared allows us to see what our eyes cannot.

Infrared thermography cameras produce images (Figure 2) of invisible infrared or "heat" radiation and provide precise non-contact temperature measurement capabilities. Nearly everything gets hot before it fails, making infrared cameras extremely cost-effective, valuable diagnostic tools in many diverse applications. And as industry strives to improve manufacturing efficiencies, manage energy, improve product quality, and enhance worker safety, new applications for infrared cameras continually emerge.

Roof moisture surveys are reliable non-invasive tools to help pinpoint the scope of moisture infiltration. This survey, whether nuclear or infrared used in conjunction with the forensic roof analysis is a dependable tool used to initiate the course of action for either maintenance and/or replacement. This vital tool will guide the corrective action to be recommended to direct and necessary repair. Our easy to follow moisture survey report consists of a written description of the results of the roof moisture survey, the calibrated tool used to identify the moisture content, methods in which the survey was performed, and a detailed color survey graph of the structure indicating our findings. The survey graph is drawn in a ten foot grid scale, as marked with orange marking paint on the roofing system, with color coding of ranged moisture values indicate the areas of moisture infiltration. These values are determined by Moisture Gravimetric Core Testing in order to identify the extent and scope of the moisture infiltration.

After a complete moisture analysis of the roof is conducted and all of the potential wet areas are marked on the roof plan, it is time to determine the true moisture content of the roof system. This is done by extracting test samples or core cuts from the roof area. Core cuts are conducted in a moisture analysis because all of the aforementioned test methods have their limitations. Moisture identified by nondestructive moisture testing is relative and must be quantified by a combination of physical core cuts and gravimetric analysis.

In the moisture analysis procedure, the core cuts are extracted to determine both the construction and moisture content of the existing roof system. For these purposes, extraction of the core cuts can be completed in the following manner for all types of roof systems:

• Identify the appropriate location of the core cut. The proper area should be representative of the entire roof area construction. Do not take a core cut from a previously repaired area.
• A core cut should be extracted from those areas determined to be dry and areas found to have varying levels of moisture presence: low, medium or high. Facilities with multiple roof areas and/or multiple roof systems require core cuts from each roof area.
• Identify the locations of the core cuts on the roof plan.
• Use a template and measure the area to be cut. Core cuts can range from 2 inches by 2 inches to 12 inches by 12 inches, depending on the amount of physical property testing that is required.
• Following the established pattern, cut the membrane, as well as any insulation and underlayment to the structural deck. Single-ply systems can be cut with scissors. Bituminous roof systems require a box cutter knife or hatchet.
• Remove all roof system components (membrane, insulation and underlayment) from the opening.
• Photograph the system components and structural deck substrate.
• Record system construction components, identifying the method of attachment of each component, including:

After proper repair of the core area is completed, the core samples should be separated and placed in a watertight container and immediately transported to an approved testing facility for gravimetric testing.

Moisture determination cannot be established solely on a visual (subjective) inspection of the materials. Standard procedures should specify that the exact moisture content of the material is determined through the use of gravimetric testing. Gravimetric testing is conducted by cleaning off the core sample components of debris and placing each component into an identical container. The core component and container is then weighed in its "wet" state. The drying process is accomplished by placing the individual component into a convection chamber for 24 hours at 230°F (114°C). After the drying process — which may include additional drying time — the samples are reweighed while still in the container. Moisture by weight is determined for each tested component by using the following formula:

*Dry Basis, of moisture=weight of moisture/oven dry weight=total weight-oven dry weight/oven dry weight

The result of the gravimetric testing provides the percentage of moisture content by weight of the tested insulation. When insulation becomes wet it loses its thermal and structural integrity. Each type of insulation has a separate percentage of moisture content at which point it loses its thermal capacity and is considered wet. Studies have indicated that even insulations that have similar chemical properties show great disparities in vulnerability to moisture.

Through the use of a Thermal Resistance Ratio (TRR), which is determined by dividing the material's wet thermal resistivity by the material's dry thermal resistivity, thus the insulation's moisture content capacity was determined. When the insulation's percentage of moisture content enables the TRR to fall below 80 percent, the insulation is determined to be wet.

The chart in Figure 3 provides moisture content by percentage of volume for common commercial low-slope insulations. If the percentage obtained in the gravimetric testing is equal to or greater than the percentage of volume listed in the chart, the tested insulation should be considered wet.

The results of the moisture analysis should be provided in report form. A roof plan accurately identifying all wet areas should be included with a report of findings, test analysis and recommendations. All wet insulation should be removed from the system to deter possible structural deck damage. If the cost of insulation removal exceeds the point of diminishing returns, full roof replacement should be considered.

Hurricanes primarily occur in the Gulf and Atlantic costal regions and contribute to widespread damage. Most hurricanes form in the Atlantic as tropical storms, when they exceed 73 mph they reach hurricane status proper system attachment is the most critical element of roof design and application. Improper attachment results in the increased probability of wind blow-offs and contributes to membrane strain created by differential movement of the system components. The design and application methods must address attachment of the total system and all of the components: substrate, roofing, flashing, metal coverings and penetrations. The most important reason for proper attachment is to prevent damage from wind force, particularly wind uplift.

Wind damage occurs primarily at perimeters and corners and infiltrates the entire system. Generally, wind vortexes occur at the perimeter of the building, displacing perimeter components (flashings, fasteners, metal coverings, etc.) and creating openings for wind entry. The wind moves through the system in a cross-directional pattern creating uplift and damage at points throughout the system. Wind uplift can also occur from below the deck in facilities that are damaged by wind from interior entry points, such as windows, doors, overhead doors, etc. Secondary wind damage can also occur at the roof from membrane protrusions created by wind-driven projectiles.

To determine the structural integrity and resistance to the forces of wind uplift Roof Leak Detection employs the tool of 5x5 Belle Chamber (Figure 4) Testing Application Standards (TAS) 124-95 testing in conjunction by our Florida State registered and licensed engineer Irv Abcug. The calculated pressure is applicable for the determination of the entire roof system—roof deck and all above-grade components. However, this procedure only determines attachment rates for the field of the roof. The pressures required for corners and perimeters must be calculated separately.

The procedure to determine wind uplift classifications on specific buildings during the design phase is based on a calculation that takes into account the basic wind speed in the geographical area, ground surrounding the building and the roof uplift design pressure at the field of the roof. The building's height and perimeter construction, and fastener type are also considered in the calculation. The combinations of both design pressure calculations and (TAS) 124-95 testing the team at Roof Leak Detection have the capability to:

• Determine the structural integrity of both existing and recently roofing systems and proper attachment.
• Evaluate compliance of Manufacturers installation and Florida Building Code Requirements.

Performance of the fastener/deck interface is a very important part of a successful roofing system. We utilize Test Application Standards as guidelines were developed to standardize the procedures used in the field to test the pullout resistance of all types of fasteners. Tests should be performed in any area where the roof has been damaged or where water or other chemicals may have infiltrated the roof system. The data developed from these tests will provide the roof system manufacturer and design professional with pullout resistance values for the specific fastener installed into the load resisting material of the deck.

Roof Leak Detection Co., Inc. uses a Com-ten digital portable pullout tester (Figure 5) utilizing a hydraulic cell. The gauge displays values in lbf and retains the maximum value achieved for accurate data collection. The gauge also allows the pullout values to fall within the working range of the gauge. The working range of the gauge is 10% to 90% of the full scale of the gauge. The fastener testing gauge also has a dated calibration certificate showing the calibrated values for the full range of the load gauge. The load gauge is also scheduled calibrated every 6 months by KELLI KIMBA LABORATORY, and if it is expected that the gauge is out of tolerance we promptly send for calibration. Calibration is performed to a standard that is traceable to a nationally recognized source. The gauge is also accurate to ±5% of the reading.

Our trained testing technicians are skilled in the pullout test procedure perform all tests. We typically perform a minimum of 10 pullouts for up to 50,000 square feet and 5 additional pullouts for each additional 50,000 square feet or portion thereof on each project. Perform the pullouts in various areas of the roof, including corners, perimeter, and field, to provide a representative sampling of performance. The location of pullouts shall allow for 50% more tests in the corners and perimeter than in the field. These standards also vary with the type of decking whether steel, tectom, wood, structural concrete, as well as the type of fastener used in said application. These elements may cause the roof deck to deteriorate and cause lower pullout values. Each roof section with a different elevation or a different deck type shall be considered a different roof and shall be tested separately. Include a roof plan to identify the location of each pullout. The roof will also be marked with marking paint with the corresponding test number of each pullout.

Roof Leak Detection Co., Inc. also performs the (TAS) 106-95 Static Tile Uplift Testing to accurately determine sufficient bonding by the mortar or adhesive to the tile and the underlayment in a mortar or adhesive set tile system and/or the mechanical attachment of components within a rigid discontinuous roof system. Our trained field test technicians utilize a calibrated Chatillion Digital Force Gauge model DFIS 100 was used to perform the tile uplift testing to a minimum of 35 lbs for a static five seconds. All testing is performed in accordance with the 2004 Florida Building Code, High Velocity Hurricane Zone Testing Application Standard (TAS) 106-95 Requirement which states " that a minimum of each corner, every two hundred square feet in the field, one in every twenty ridge/rake/hip tiles (where applicable), and every ten feet along the perimeter tiles."). We mark each tested tile with either a T (pass) or F (fail) in crayon for further inspection and repair.

All testing is performed Figure 6 in conjunction with a detailed visual inspection and a concise report that contains a scale drawing of the structure, findings of the testing, and test summery. Digital photographs are also taken to document and identify deficient conditions for further inspection and repair. Our report is often used by our clients for various applications:

• Submittals to county building officials as necessary for final inspection
• Submittals to insurance companies as part of an existing claim
• To aid in determining if the roof can be repaired or re-roofed
• To assist in quality control verification

*A roofing professional shall be present to repair the roof in areas where the tests were performed to ensure that it is returned to a watertight condition

Our Roof Asset Management program is intended for clients with large or multiple roof assets. The program is most beneficial for clients that have no established roof program and no qualified in -house personnel to inspect or to maintain the roofs. The program can however be modified for clients with as few as one or two roofs. We can tailor the program to suit individual client requirements and budget constraints. However, to make the program most beneficial, we suggest that it include the following:

Semi-annual roof inspections should be performed either the Spring and/or the Fall. This service is typically performed in conjunction, but not limited with our testing services. Thorough diligence is taken will tediously inspecting the roofing project for any flaws, deficiencies, or areas of repair to ensure tight quality control. Our clients expect that their roofing project is undertaken by skilled and trained installers to ensure that the project meets not just the Manufacturers Florida Building Code, but our methods of quality control. In addition, a roof inspection should be performed after every major weather occurrence. After the initial roof inspection is complete, and with some training, building maintenance personnel could assist in performing a scheduled maintenance in conjunction with the semi annual inspections. We would still be advisable to have a professional inspect the roofs at regular intervals.

We are approved by the State of Florida as a private inspections provider. As such, we can assist our clients with in progress inspections when the City is not able to do so in a timely manner. Once we have verified that the roof meets current code requirements, we will issue a certificate, which the client can submit to the City having jurisdiction. Though the municipalities may vary in their methods, the process involved in Private Provider inspections is usually as follows:

Impact damage may not always be clearly visually evident and is often underestimated. In order to fully determine the extent of the damaged roof membrane additional laboratory testing might be required. Desaturation testing is a process in which a core sample of roof membrane is taken and analyzed via solvent extraction. The extraction process removes the bitumen from sample and clearly exposing the reinforcements and its internal composition. Roof membrane desaturation testing performed by the team at Roof Leak Detection has the capability to:

• Determine the complete composition of the sample.
• Identify structural damages to the individual layers of reinforcements within the sample.
• Identify functional and mechanical damage to the individual layers of reinforcements within the sample

METHODOLOGY: Roof membrane samples are taken from the existing roofing system for desaturation testing. Desaturation testing is the defined as the removal of the existing asphalt components from a sample utilizing a vapor degreaser in order to extract the internal reinforcements for analysis.

The surfaces of each sample is visually inspected on both the top and bottom to identify areas of potential hailstone impact damages including, but not limited to: punctures, tears, and/or bruises.

Each roof sample is weighed and measured for length and width. The roof sample is then outlined on Mylar sheet overlays and each area of concern is marked. The roof sample is desaturated in a vapor degreaser and the reinforcements are extracted. Finally the roof sample and the areas of concern are scientifically scrutinized visually, manually, and microscopically.