Roof purline is adopted with cold-bending and thin-wall steel (Q345), knee bracing, roof horizontal bracing and purline drawn rod Q235.

本工程屋面檩条采用高冷弯薄壁型钢材质Q345，隅撑，屋面水平支撑，檩条拉条材质均为Q235。

youdao

If you would demand a good faith estimate from a contractor to fix a leaky roof, it only makes sense to demand the same from a doctor to fix a creaky knee.

FORBES: To Bring Healthcare Prices Down, Consumers Must Demand Price Transparency