Which of the following is NOT a common walkway material?

The answer indicates that wooden panels are not a common walkway material in the context of BUR (Built-Up Roofing) systems.

In roofing applications, especially for built-up roofs, the primary focus is on durability and weather resistance. Walkway materials are selected based on their ability to withstand foot traffic and environmental conditions without damaging the underlying roofing membrane.

Asphalt planks, modified bitumen (MB) cap sheets, and rubber or plastic pads are all specifically designed materials that can provide adequate protection for the roofing system while allowing for safe pedestrian access. These materials are typically flexible, resistant to wear and tear, and suitable for varying weather conditions, which is essential in roofing applications.

Wooden panels, while they may be used in other construction applications or temporary setups, are generally less durable in the context of roofing. They can be susceptible to rot, moisture damage, and may not provide the necessary longevity required for a rooftop environment. Thus, they are less favored compared to the other options listed.