Hi @junglejellybean,
I would say they are more likely screws than nails. These are what they often refer to as "screw pops", which happens when the head of a screw that was fixing the sheet to the ceiling frame pushes forward and becomes visible under the paint or plaster. Instead of sitting flush and secure, the screw shifts slightly, creating a small bump or, in some cases, even breaking through the surface coating.
In some cases, the screw will have pulled through the paper face of the plasterboard, which reduces the holding power of the screw to next to nothing.
My suggestion would be to start by drawing a straight line between the screws, as this should show you the location of the ceiling framing. You could then use a Stud Finder to confirm this.
After marking the stud location, you can drive some 30mm Plasterboard Screws through the plasterboard into the framing above. You should add an additional screw around 100mm from each screw pop. When driving the screw in, you want it to just purse the surface of the plasterboard. If you drive it in too far, it will pull through the paper face of the plasterboard, which has no holding power. If you get it close with a drill or impact driver, you can manually tweak it with a screwdriver so that the screw head sits just below the surface of the plaster board.
With these additional screws in place, you can then use a Craftright 100mm Joint Knife to scrape the paint and any damaged plasterboard away from the screw pops. You can then remove these screws as they are no longer needed.
After securing the sheet and removing the old screws, apply some UNi-PRO Multi Purpose Interior Filler over the screws and the holes from the removed screws, allow it to dry, then give the filler a sand with a sanding sponge.
Once sanded, brush down the surface to remove any fine plaster dust, then prime and paint to match the rest of the ceiling.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
