b'PMRArole in delaying water drainage, especially at lower rainfall intensities with multiple insulation layers. To accurately assess the thermal transmittance Insummary,theseresultsempha-sizetheneedforthoroughevaluationof PMRA systems, it is essential to account for of all roofing components to optimize thermal resilience and energy efficiencylocal weather conditions such as rainfall intensity, in rainy environments.TASK 3: CODIFICATION AND STAN- temperature fluctuations and humidity, as these DARDS INTEGRATIONThetwoprimarythermalimpactinfluence material selection and seasonal performance.factorsUand U , as defined LTC raininEquation1weresystematically quantifiedthroughnewlydeveloped testmethods.Toaccuratelyassess thethermaltransmittanceofPMRA systems,itisessentialtoaccountfor localweatherconditionssuchasrain-fallintensity,temperaturefluctuations and humidity, as these influence mate-rial selection and seasonal performance. Twosimplifiedcalculationapproaches werecreatedtoestimatetheaverage effectofclimateonroofthermal behaviour: one based on hourly climate data, and the other on seasonal weather patterns. Both methods used experimen-tally derived relationships between rain-fallintensityandtransmittancelosses for the different tested PMRAs to calcu-lateU theaverageimpactof rain,avgrainonthermaltransmittance.Several assumptions were made for simplifica-tion: only rainfall during heating periods (when outdoor temperatures are below indoortemperatures)wasconsidered; precipitationwasonlyincludedwhen outdoortemperaturesexceeded0C (32F) to exclude snowfall; thermal mass of the pavers and roof was neglected; andindoortemperaturewasfixedat22C (72F).Table 4 illustrates the application of theseasonalcalculationprocedurefor four PMRAsPMRA-2, PMRA-8 and PMRA-18acrossmultipleCanadian locations.Thismethodestimatesthe annualimpactofprecipitationon thermalperformancebycombining averageseasonalclimatedatawith regionalstatisticsonrainfallquantity andintensity,categorizedintodefinedintensity ranges.The procedure differentiates between rainy and non-rainy periods during the www.rcabc.orgl27'