Each under-deck system is constructed from different materials; many are built from either aluminum, vinyl, or steel.  Be aware of the warranty that comes with the product and the properties of each material; a standard warranty covers the system for a predetermined amount of time, but others may protect against wear and tear for the lifetime of the deck.  Under-deck systems typically come in a limited range of colors.

Copper in wood.  Recently, the Environmental Protection Agency banned the use of arsenic to treat wood, because of health risks.  A safer copper-based treatment has emerged as the dominant method.  However, small amounts of copper may drip down from the wood and come into contact with the ceiling system, so manufacturers should take precautions to minimize potential corrosive effects.