The best material to build an outdoor deck with is really a multi-layered question. First, you need to have the substructure, consisting of the posts and joists.For the substructure, the best material to use is a pressure-treated lumber. Pressure-treated lumber comes in different sizes, like lengths, widths, thicknesses. You also want to be sure to use nails and/or screws that are rated for outdoor use.
Secondly, you would need to choose a material for the actual decking boards themselves. There are really two different types of decking that I recommend to use, and it’s totally up to the person that wants this deck. There’s a traditional five-quarter board and there are composite decking boards. The difference between the two is that five-quarter boards will need to be maintained at least once a year with a Thompson’s water seal or a water sealing stain of some sort. If this is not done on a regular basis, then you can probably expect your deck will eventually need boards to be replaced.With the composite decking, there is virtually no maintenance other than the occasional power washing. Composite decking is made up of wood and polymers mixed giving it a real wood look, but the durability of polymers. You can expect a composite deck to last for years and years with very little maintenance. But with that being said, there also comes added cost. Composite decking is about double the cost of traditional five-quarter treated lumber. I guess it’s all in the amount of effort someone wants to put into maintaining their deck.
Lastly, you would need to make a decision on the railing material for your new deck. Again, you have choices. There is traditional wood railing and with that comes maintenance again. Second, there are composite railings, which again—maintenance-free, but hefty cost wise. Lastly, there are vinyl railings. The vinyl railings nowadays are much better quality then they were even as little as 10 years ago. Ten years ago, I would have never recommended a vinyl railing due to the poor quality that they were constructed with. They were just cheap and flimsy, but now they’re a good quality product with a decent price point and are as maintenance-free as composite materials. That’s my advice for someone who wants to build a deck or have a deck built.