HELPING THE OTHERS REALIZE THE ADVANTAGES OF ROOF DRAIN

Use wooden stakes and Mason’s line or chalk line to produce a square or rectangular form across the marked space. Be certain the formwork is amount and protected. When setting up the formwork, make allowance to the slope towards the center of the drain.เมื่อน้ำฝนหล่นกระทบกับหลังคา ก็อ�