Which roofing material is identified as not ideal for steep roofs?

Rubber membranes are considered not ideal for steep roofs primarily due to their design and intended application. Rubber roofing systems are typically utilized for low-slope or flat roofs because they provide excellent waterproofing and are seamless, but they lack the necessary traction and water shedding properties required for steep roofs. When used on steep slopes, rubber membranes can be more prone to leaks, water build-up, and potential slippage as water can pool rather than drain away efficiently.

In contrast, asphalt shingles, copper sheeting, and clay tiles are popular choices for steeper pitches. Asphalt shingles are designed to adhere well to various pitch angles, while copper provides durability and aesthetic that performs well on slopes. Clay tiles are specifically made for high-pitched roofing, allowing for appropriate drainage and ventilation. Thus, when considering roofing materials for steep roofs, the characteristics and performance of rubber membranes make them less suitable compared to the other options.