ท่อน้ำฝน - An Overview
Use wooden stakes and Mason’s line or chalk line to create a square or rectangular form within the marked spot. Make sure the formwork is amount and secure. When making the formwork, make allowance for that slope in the direction of the center from the drain.รางน้ำฝนสังกะสี เป็นวัสดุที่ยอ