I need to re-seal a deck on a house that I'm getting ready to rent out, it has Thompson's Water Sealer on it now and it's failing from the sun exposure. How much prep is necessary with this stuff? I've already dug all of the mulch out from between the boards and I'm about to power wash it really well, do I need to sand the whole thing down before re-coating it?
It's a huge deck and I'm not looking forward to sanding it down...any advice is appreciated as long as you're not just guessing.
Pictures of the worst parts:
