Moisture mapping of roofs is a technique used to identify areas of moisture infiltration or accumulation within roofing systems. Here’s a detailed description of how it’s done:

Preparation: Before moisture mapping begins, the roof surface needs to be clean and dry to ensure accurate readings. Any debris or standing water should be removed, and the roof should be allowed to dry if it has recently been exposed to rain or other moisture sources.

Selection of Method: There are several methods available for moisture mapping, each with its own advantages and limitations. Common techniques include infrared thermography, nuclear moisture meters, capacitance meters, and electrical impedance meters. The choice of method depends on factors such as the type of roofing material, accessibility of the roof, and budget constraints.

Instrument Calibration: Regardless of the method chosen, the moisture detection instrument must be properly calibrated according to manufacturer guidelines to ensure accurate measurements.

Data Collection: Moisture mapping typically involves systematically scanning the entire roof surface, either manually or using automated equipment such as drones equipped with moisture detection sensors. For methods like infrared thermography, data collection is usually conducted during daylight hours when temperature differentials between wet and dry areas are most pronounced.

Analysis: Once data collection is complete, the collected data is analyzed to identify areas of moisture infiltration or accumulation. Infrared thermography, for example, produces thermal images where moisture appears as cooler spots due to its higher thermal conductivity compared to dry materials. Other methods may provide numerical readings indicating moisture levels.

Interpretation: Interpretation of the moisture mapping results requires expertise to distinguish between actual moisture presence and false positives caused by factors such as surface contaminants, trapped air, or variations in substrate composition. Experienced inspectors use their knowledge of roofing systems and moisture behavior to make accurate assessments.

Reporting: The findings from the moisture mapping survey are compiled into a detailed report that outlines the location and extent of moisture damage, as well as recommendations for remediation. The report may include annotated diagrams or images highlighting problem areas for reference.

Follow-Up: Depending on the severity of the moisture damage detected, follow-up actions may be necessary, such as repairs, waterproofing treatments, or roof replacement. Follow-up inspections may also be conducted to verify the effectiveness of remedial measures.

Moisture mapping is a valuable tool in roof maintenance and inspection, allowing for early detection of potential issues that could lead to costly damage if left unaddressed. By accurately pinpointing areas of moisture infiltration, property owners can take proactive steps to protect their investment and prolong the lifespan of their roofing system.