It affects both the A55 expressway and the A483 south of Chester.
There will be one lane open on the A483 northbound on to the roundabout, but vehicles will not be able to turn right on to the eastbound A55.
Overnight closures affect the western side of the roundabout, and the northbound carriageway from Pulford.
Restrictions will be in place until 05:00 BST on Monday.
Highways England, which is overseeing the Â£6m improvement project, said the roadworks should be finished by 28 June.
Work on the roads was originally due to be completed in March, prompting complaints from local politicians on both sides of the Wales and England border.
Motorists are warned about lane closures around the Posthouse Roundabout between Wrexham and Chester on Saturday and Sunday.