DETAILED NOTES ON ท่อน้ำฝน

8. Right air flow also needs to be taken into consideration when developing a concrete drain over a flat roof. Ample airflow is important to forestall moisture buildup, which may lead to destruction and deterioration from the roof.เมื่อน้ำฝนหล่นกระทบกับหลังคา ก็อาจกระเด็�