Irthlingborough drivers face A6 weekend closure for viaduct repairs
Motorists using the A6 at Irthlingborough must plan for significant travel disruption as North Northamptonshire Council prepares for a full weekend road closure. Engineers discovered that the concrete deck of the Irthlingborough viaduct is in a much worse state than initial surveys suggested, requiring an immediate shift in the maintenance schedule to ensure structural safety.
To manage the impact on local traffic, the council has confirmed the following closure window for the end of May:
| Date and Time | Traffic Impact |
|---|---|
| Friday 29 May, 8pm to Monday 1 June, 6am | Full road closure in both directions |
| Monday 1 June, 8pm to Tuesday 2 June, 6am | Contingency closure window |
Unexpected concrete decay halts original repair plan
The current situation stems from findings during the initial construction phase on May 8, 2026. While the team was on-site to begin re-waterproofing the structure, they identified challenges that were not visible during earlier trial hole investigations. The concrete deck was found to be in a considerably poorer condition than previously recorded.

This unforeseen deterioration forced an immediate revision of the project scope. The upcoming weekend closure is essential for the engineering team to fully assess the extent of the damage across the viaduct. This assessment is a critical step in ensuring the longevity of the bridge and the safety of the thousands of vehicles that cross it daily.
Long-term structural repairs moved to Summer 2026
The Irthlingborough viaduct serves as a vital link in the North Northamptonshire road network. Waterproofing is a necessary preventative measure designed to stop water and road salt from corroding the internal steel reinforcements of the concrete. Because the decay is more advanced than expected, the full re-waterproofing program has been pushed back to allow for more intensive structural preparation.

Comprehensive works are now scheduled to take place in Summer 2026. North Northamptonshire Council has stated that updates regarding the summer timeline and any further changes to traffic management will be published via the North Northants Highways social media pages. Drivers are encouraged to check local traffic portals for diversion routes before the May 29 closure begins to avoid the expected bottlenecks in the Irthlingborough area.
Source: North Northamptonshire Council