We check the frame first, honestly
The inspection looks at the ledger and its flashing, the footings, the posts at ground contact, the joists and hangers, and the joist spacing. Rot shows up most often at the ledger and at the base of posts, and both are where failure actually matters.
If the frame will not carry a composite surface safely, we say so and quote a rebuild instead. Putting a twenty five year board on a frame with five years left in it is a waste of your money, and we will not do it.
Joist spacing decides what can go on top
Older decks were often framed at spacings that suit five quarter wood but are too wide for some composite boards, particularly when the boards run diagonally. Where that is the case the fix is usually sistering in extra joists rather than abandoning the project, and it is a modest addition to the work.
What a resurface includes
New composite walking surface, new fascia so the frame does not show, new railing, and stair treads and risers rebuilt to match. Lighting can be added at the same time, and this is the cheapest moment to do it: the boards are already up, so running the wire costs almost nothing extra in labour.