What material is not suitable for above-ground drainage according to the standards?

Polyethylene (PE) is not suitable for above-ground drainage as per plumbing standards due to its characteristics and physical properties. While PE is often used in underground applications and for some specialty fittings, it lacks the structural integrity needed to withstand the potential external forces encountered in above-ground drainage systems.

Additionally, PE is more flexible and may deform under varying temperatures or load, resulting in a higher risk of leaks or failures if subjected to conditions typical in above-ground installations. On the other hand, materials like ABS, PVC, and cast iron are recognized for their durability, resistance to environmental factors, and suitability for above-ground applications, making them preferred choices for such systems.