The work, between junction 16 (for the M40) and junction 17 (at Maple Cross) will involve the replacement of bridge expansion joints which have reached the end of their serviceable life. Expansion joints help to protect the structural integrity of a bridge by allowing it to expand and contract with seasonal changes in temperature.
The work will be carried out in two phases, each using overnight carriageway closures.
Highways Englands project manager, Stephen Hall, said:
We are carrying out this improvement work at night to minimise disruption to road users. Its essential that the work takes place so that drivers can benefit from safer journeys.
The first phase of work will include overnight closures of the clockwise carriageway of the M25 between junction 16 for the M40 and junction 17 for Chorleywood. Closures will be in place overnight, between 10pm and 5.30am, from Wednesday 9 September until Sunday 13 September. The closure on Friday will be between 11pm and 6am.
A clearly signed diversion will be in place via the eastbound M40, northbound A40 Oxford Road, northbound A412, then via the North Orbital Road to M25 junction 17.
A second phase of work will take place overnight, between 10pm and 5.30am, on the anti-clockwise carriageway from Monday 14 September until Thursday 17 September.
A clearly signed diversion will be in place via the North Orbital Road, southbound on the A412, eastbound A40 Oxford Road and then westbound M40 towards junction 16.
Further work to replace expansion joints on the M25 in Kent will take place later in the year.
Members of the public should contact the Highways England customer contact centre on 0300 123 5000.
Journalists should contact the Highways England press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.