I've got several sheets of 8' x 4' floor grade chipboard, mostly tongue and groove going spare. Tongues a bit damaged but otherwise OK
Best offer secures - If your offer is take away for free and it's the best one you can have tham for free.
Also available in 8x4 sheets, 12mm ply and some 50mm celotex
Located near Bath in North West Wilts
email me info at broadband4box dot co uk if you're interested
Nick