ท่อน้ำฝน Fundamentals Explained
Use wood stakes and Mason’s line or chalk line to create a sq. or rectangular shape around the marked space. Make certain the formwork is stage and protected. Although creating the formwork, make allowance for the slope to the middle from the drain.อ้างอิง-ภาพ : สำนักงานทรัพยากรน้ำแห