Because solid 6x6 wood structural posts are prone to checking, over time they can become an eyesore. Wrapping the support posts with an aluminum or vinyl cover can be a nice finishing touch to conceal the posts and also to protect them from the sun. There are many products available in different colors and styles. Accessories to cover and decorate the bases and top connections may also be available.
Some composite decking manufacturers also produce post sleeves that match the color and texture of the decking’s appearance. Composite post sleeves are usually hollow cores that you must slide the post into before installation. Most aluminum and vinyl covers are sold as assemblies that can be snapped together around the post after it is installed.
Some deck builders use rough sawn cedar as trim to wrap structural posts. This offers a kind of bittersweet solution because although this may look nice to begin with, it will eventually weather and crack just as the post underneath would. Decks that are installed over garages may require you to surround the base of the structural posts in concrete as a precaution against being struck by an automobile.
Here is an example of wrapping a deck's support posts with a composite material to match the fascia and railings.
