What material is used for the connection between the roof and the roof drain that passes through the roof?

The connection between the roof and the roof drain must be weather-resistant and durable to effectively handle water runoff and prevent leaks. Lead or copper flashing serves this purpose well due to their excellent waterproofing properties. Flashing is designed to direct water away from critical areas of the roof, ensuring that it flows into the drain rather than seeping under shingles or roofing materials.

Lead and copper are also malleable metals, meaning they can be easily shaped to fit the contours of the roof and the drain. Copper, in particular, has additional benefits such as resistance to corrosion over time and a long service life. These qualities make lead or copper flashing the preferred materials for ensuring a watertight seal at the roof-drain connection.

Other materials like plastic tubing, stainless steel, or aluminum sheets do not typically provide the same degree of effectiveness or durability when used in this specific application. For instance, while plastic tubing is often used in plumbing systems, it may not provide adequate protection against the elements or the structural integrity needed for a roof-penetrating drain. Similarly, stainless steel, though strong, is generally more expensive and may not be as easily molded into the required shapes compared to lead or copper flashing.