The bridge across the River Witham on Bridge End Road, Grantham, will be closed to traffic from Monday, March 25, for three weeks for maintenance work.
Diversions will be in place for motorists passing through town. The work is scheduled to finish on April 15.
David Walton, client and contracts service manager at Lincolnshire County Council, said: “During routine maintenance in 2012, we identified a waterproofing problem with the A52 (Bridge End Road) bridge but we were not in a position to carry out the work at that point due to other planned works in the area. Work to fix this problem will now start on March 25 and will be completed by April 15. Local diversions will be in place.
“We are waterproofing the deck of the bridge. This involves taking up the road surface, cleaning the concrete deck and then spraying it with a liquid resin compound, and then resurfacing it with the road.
“We apologise to motorists for any inconvenience that this work may cause, but we have scheduled this maintenance around the half-term school holiday to minimise disruption.”
Traffic passing through town on the A52 heading west will be diverted along the B6403 High Dyke to Ancaster and then via the A153 to Grantham, and vice-versa.