INDICATORS ON ROOF DRAIN YOU SHOULD KNOW

eight. Proper ventilation also needs to be taken into consideration when building a concrete drain on a flat roof. Enough airflow is necessary to circumvent humidity buildup, which may result in damage and deterioration on the roof.อ้างอิง-ภาพ : สำนักงานทรัพยากรน้ำแห่งชาติ