Evaluation of clay tile roofing as a cool roof

摘要

This study was designed to evaluate a traditional tiled roof as a double skin (or cool roof). In the general method of construction, a traditional tiled roof is finished as a two-layer structure. Our main interest was heat exhaust via ventilation from the air layer found in this two-layer roof structure. We verified this effect by creating scale models and conducting field tests. Every portion of the air layer in the roofs of these models was sealed to isolate the airflow from the outside. As a result of the testing, we recognized the presence of airflow in the air layer between the roof tiles and the roof board, and this airflow lowered the temperature in this air layer. The causative factor may be airflow (draft) through gaps in the jointed portions of the roof tiles. In order to confirm the impact of this factor, we performed a numerical simulation. As a result of actual field tests, we were able to identify airflow (draft) through gaps on the roof surface layer and similar airflow in the air layer of the double skin.