Welcome,I will do my best to help you with your issueSince it sounds like the patio is open to the weather I'd suggest tongue and groove vertical wood paneling. You don't say where you live so I don't know what's most available where you are but here in New England V groove pine is most common. It's also available in a bead board pattern instead of V groove. You can paint or stain it and it will give your patio a more finished look. It's also pretty easy to install.