The choice between Trex, a brand of composite decking, and PVC decking depends on your priorities regarding budget, appearance, and environmental impact. Both materials are durable and resistant to moisture and insects. Trex is often considered more eco-friendly because it contains recycled wood and plastic and is 25% recyclable, while PVC is fully synthetic and harder to recycle. Aesthetically, Trex is designed to look more like real wood, whereas PVC often has a glossier, more plastic-like finish. In terms of cost, Trex is typically less expensive than PVC.

Staining and sealing the underside of a deck creates a moisture barrier but traps water in the boards, quickly leading to rot. No matter how well you seal the above deck, water still gets through via nails and screw heads on the surface. Allow this water to flow naturally under the deck, where it is routed through the drainage system.

You can build an outdoor kitchen on a deck, but you should choose composite decking since it's more heat-resistant. Metal deck materials like steel and aluminum are also good choices because they're less flammable than wood. You should also consider the weight of the kitchen—make sure your deck can support it and any appliances you plan to use. You should consult a structural engineer to confirm exactly how much weight your deck can safely support when building an outdoor kitchen. 

Generally, a patio is more accessible than a standard deck because patios are constructed at ground level. However, decks can be made accessible by adding a wheelchair-accessible ramp, a vertical lift, or a stair lift along the entry. An ADA-compliant deck ramp costs about $3,000 on average. The additional investment will provide a much friendlier experience for your guests with movement impairments.