The westbound carriageway will be closed between 9pm on Friday, 26 September and 6am on Monday, 29 September while the work is completed.
Chris Pope, Highways Agency project sponsor, said:
The Severn Bridge is a vital transport link between England and Wales, and this work will help keep it operating safely for many years to come, as well as providing a smoother surface for road users.
We have planned the work carefully to cause the least possible disruption and will also be taking the opportunity during the closures to carry out other work such as inspection and maintenance work to barriers and lighting, grass cutting on the verges and painting posts to reduce the need for traffic management in the future.
Road users are advised to plan ahead and allow slightly longer for their journeys.
While the bridge is closed the following signed diversions will be in place:
Road users travelling westbound to Chepstow should use the M4 Second Severn Crossing, exit at J23a (Magor), then follow the M4 eastbound, then follow the M48 to Chepstow.
Members of the public should contact the Highways Agency Information Line on 0300 123 5000.
Journalists should contact the Highways Agency press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.