I'm making some outdoor storage bins as the ones in garden centres are too flimsy. I've previously built a shed, so I made a bin out of plywood and OSB, covered the lid with roofing felt, treated the wood but I'd rather have made it out of waterproof no-maintenance material.
Can anyone suggest a waterproof sheet material, natural looking, strong, hard wearing and can be cut and drilled? E.g. a modern substitute for cement-bonded asbestos sheet, but even better? I couldn't see anything obvious in B&Q. Thanks in advance...