Mark Bluemel pretended :

The framework is fine, so I hope to simply put up a new board,
probably with a couple of layers of decent felt.

What board should I use? OSB? WBP ply? Something else?

What about using some of that clear plastic corrugated roofing
sheeting?

I used it for a covered area I made at the back of our summer house
several years ago, built on to the wind sheltered side and its still
fine. It lets light in and some winter heat from the sun, so maybe
would help logs dry out.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk