On a deck that is constructed and not attached to the home, is that within the scope of inspection. I have only found attached decks to the dwelling to be inspected in my studies.
The scope of any inspections you offer is determined by the SOP of your state(if licensed) and NACHI and you contract with the client.
Be more specific with your description of “not attached to the home”. A “Free-standing” deck could be “Not attached to the home” and be only an inch away from the structure, and be included in most SOP’s. Complete and exact details are crucial to getting a correct answer to your, or any, question.