I have about 22 years old wood deck in a house that I bought about year ago. It is about 1000 sq feet deck. But the wood has deteriorated quite a bit.

So I am having a handyman replace the wood boards (has some experience but not very knowledgeable, but good pricing). I am having all boards replaced with pressure treated premium lumber. He just started taking out old lumber today.

Questions I have are:

1. While I have the underlying framing exposed, should I take opportunity to apply sealant on those wood before putting on new deck or that is not necessary?

2. what materials I could put on the ground to avoid moisture problems in future? We are planning to have solid skirting (secondary to problems with raccoons etc), but will try to keep some vents

3. After I put on the new lumber, how long to wait before staining? After reading some posts here, seems TWP100 is mostly recommended. It seems newer recommendations are to stain quickly rather than waiting for months. Is it worth to buy moisture meter to check moisture before staining?

thank you all for your response