Road surfacing work across Lincoln has been redone after council contractors used sub-standard materials.Lincolnshire County Council has been forced to repeat surface work after contractor May Gurney failed to deliver an adequate service in September, last year.The disruption has led to anger among both residents and business owners.Lincolnshire County Council said it expected a new road surface to last for up to 20 years.The authority said the work was general road maintenance and not part of a specific project.Senior highways officer Dave Underwood told the Lincolnshire Echo: "The material used by our contractors to resurface these roads last summer just wasn't up to the standards we require."We have done our best to keep disruption to a minimum, getting signs out early, sending letters to residents and businesses and putting information under the windscreen wipers of vehicles."The council, which will not foot the bill for the second round of roadworks, refused to say how much the contact with May Gurney was worth. May Gurney declined to comment.