To ensure watertight integrity, a scupper must be lined with what?

A scupper is an essential component designed to allow water to drain from a flat or low-sloped roof, preventing water accumulation that could lead to leaks and structural damage. For scuppers to maintain watertight integrity, they must be lined with a material that can withstand exposure to water over time and resist corrosion.

Metal is the correct choice for lining a scupper due to its durability, strength, and ability to form a tight seal, helping to prevent leaks. Metal scuppers can include materials like aluminum or galvanized steel, which are often treated or coated to enhance their corrosion resistance, especially in outdoor conditions where they will be subjected to rain and other weather elements.

Using plastic, rubber, or wood would not offer the same level of long-term reliability. Plastic might be too brittle or susceptible to UV degradation, rubber can wear down over time and become ineffective, and wood is prone to rot and decay when exposed to moisture. Therefore, the use of metal ensures that the scupper functions effectively, maintaining the integrity of the roofing system and protecting the building from water damage.