The deck joint on the east side of the Holyport interchange needs to be replaced.
The work will take place overnight between 10pm-6am, starting on Monday, February 18. It is expected to run for five nights.
The closure affects drivers travelling south on the A404(M) or A308(M) wanting to join the M4 westbound, and those coming from the A308(M) to travel north on the A404(M).
Drivers on the M4 westbound needing to exit at Junction 8/9 to travel north on the A308(M) or A404(M) will be unaffected.
The diversion, which will be clearly signed, involves drivers joining the M4 eastbound, exiting at Junction 7 and travelling north on the Huntercombe Spur road to the roundabout at the junction with the A4 Bath Road.
Drivers must go around the roundabout and exit in the opposite direction along Huntercombe Spur, re-entering the M4 westbound towards Reading.
Highways Agency project manager Emily Collins said: "This essential work will improve driving conditions, ensure ongoing safety for road users and reduce the need for future unplanned closures.
"We have planned the work carefully so that it can be completed safely, efficiently and with minimum disruption to road users.
"We are advising road users to plan their journeys before they set off so they can avoid potential delays."