The use of wood in deck construction has become more popular with the introduction and availability of various types of weather and rot resistant lumber. Such products have made deck construction and maintenance easier and less expensive than before.
Wood rot and weather resistance depends upon the type of wood used and its applications. Some of the wood choices available on the market include:
The use of cedar or redwood in decks requires careful selection of material. Young sap-wood material may have very little resistance to rot. Old heart-wood material has much better resistance to rot but is hard to find and quite expensive. But no matter how good the quality of the cedar or redwood, decks made out of these materials will require frequent treatment with a wood preservative.
Treated lumber can last for decades with relatively little maintenance and repairs. The decking should be coated with a penetrating finish in order to reduce wood cracking. Pieces that are cut or shaped during the construction maybe subject to wood rot damage in the areas where inner/untreated sections of a board are exposed. And this decking, like almost all others may have to be pressure washed and treated for moss in order to keep the deck from becoming slippery.
This is a relatively new lumber product on the market. It seems like a very promising and low maintenance product. But I do suspect that even Ipe will succumb the our Seattle area rain and have to be cleaned and treated in order to prevent it from becoming slippery.
Composite wood can be worked with most wood-working tools. Its heavier per unit than the other options and bends more easily. As such, it may require closer joist spacing. I have seen many decks and outdoor public structures made out of composite woods and have been impressed with the results. I have also seen two decks with surface damage produced by the paws of the family dog - I have no idea if or why that might be a common problem.