Those of you paying attention will know that I have been constructing
cavity brick sub walls to infill an agricultural steel frame barn. Today
I am celebrating laying the final brick!

The next move is to fabricate sectional Oak framing to sit on the
brickwork and fill the gaps between the stanchions. As we are
approaching Winter weather, I am getting nervous about exposing my
carefully seasoned Oak to rain and frost.

The original plan was to fit 50mm Kingspan/Celotex to the exterior and
clad with feather edge boards on battens. I am now wondering if there is
an affordable weatherproof board which can double/treble as protection
for the frame, vapour barrier and visible interior finish?

I have enough 12mm ply to do about half the job. Presumably a stiff coat
of oil based paint would sort the vapour barrier issue or is ply OK on
its own?

regards
--
Tim Lamb