ระบบระบายน้ำฝน Can Be Fun For Anyone
Use wooden stakes and Mason’s line or chalk line to make a sq. or rectangular condition around the marked place. Ensure the formwork is degree and secure. Whilst setting up the formwork, make allowance for that slope in the direction of the center in the drain.เมื่อน้ำฝนหล่นกระทบกับหลังคา