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. 

While you can use various materials like sand or even just soil, gravel is widely considered the best option to put under a deck. It provides excellent drainage and is resistant to water, fire, and pests. Gravel also helps anchor the soil to prevent erosion during heavy rain and acts as a built-in weed blocker, reducing regular upkeep. Furthermore, it is simple to spread, available in various textures and tones, and adds a polished look that complements any deck design.

PVC decking might be long-lasting, but this synthetic material lacks​​ the natural aesthetic or sustainability of wood decking. If you want to match your decking to your new garden furniture or just freshen up the faded surface, it’s not usually possible to paint PVC decking. When comparing PVC to composite decking, PVC is pricier and more prone to warping in hot regions.

Many people say the best composite decking is Trex, TimberTech, or Fiberon. These brands have formulated composite deck boards to withstand the elements and hold up over time. Each offers a range of product lines varying in durability, price, and appearance. Compare their different composite decking offers for cost, looks, and features before deciding on a product.