I’m not sure what a super66 fence is. Are you in Australia?

i would be asking the Colorbond fence manufacturers about the expected strength of the fence and advice about correct installation....correctly installed the fence should be OK but doesn't matter how good the fence is if a gate is left open...rather than a different adjoining fence i'd want the neighbour to restrain their dog within a separate secure yard built within their own property and would also ask the Council about dog restrictions in your area...

Kate, super6 is a term commonly used for the 6 foot, asbestos or Hardie fence, used in suburbs across Australia. Before colorbond metal became a product used.

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Oh an Old asbestos fence material.

Hi, I'm an Asbestos assessor by trade. If the paint doesn't hold up, you could possibly build another fence next to it or cover the painted super 6 with corrugated PVC as extra protection. Or you could ask your local demolition guys to salvage some corrugated steel next time they do a roof and touch that up with a bit of paint.

Just note you'd need dust suppression and containing methods, low-set power tools or hand tools, and protective equipment when fixing the PVC/ steel fence to the super 6 (and probably chain-mail armor when entering the dog's territory ;-) ).