The bridge will be closed in the eastbound direction, so affecting drivers travelling from South Wales in the direction of Bristol.
Drivers are being diverted over the old Severn Bridge, via the M48, and congestion is to be expected for drivers until the M4 reopens.
Further information on the bridge closure is available from National Highways by visiting their website and travel apps, or via the regional X feed.
They also have a 24/7 contact centre team available to provide up to the minute information on 0300 123 5000.
Work on the new Severn Bridge has been ongoing since July, as National Highways need to re-waterproof and resurface a 1km stretch of the cable stay bridge to extend the life of the road surface.
They aimed to maintain as much capacity as possible by keeping 2 lanes running in both directions and in instances where a full closure is needed, they offer the M48 Severn bridge as an alternative route.
