Hi @Caecilia,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
You have some beautiful plasterwork in your home, so I understand your worries.
To start with, if your home is pre-1970, then there is a chance that lead-based paints were used. If you have concerns that your home may contain lead-based paints, it would be worth having it tested prior to commencement of any work.
With older federation-style ceilings, the main priorities are preserving the decorative plasterwork and preventing further damage. Peeling paint and fine cracks are very common in homes of this age, but they need a careful touch because plaster mouldings are delicate and hard to replace once damaged.
The safest approach is to gently remove only the loose paint rather than aggressively scraping back to bare plaster. Use a flexible filling knife such as this Craftright 100mm Joint Knife and work slowly so you don’t chip the mouldings. After that, lightly sand the edges where the paint meets bare areas with a Fine Sanding Sponge so the surface feels smooth under your fingertips. For cracks, open them very slightly with the corner of your joint knife (so filler can get in) and then fill with a plaster topping compound such as this Less Mess Topping Compound. Once dry, sand it flush with the surrounding area using your sanding sponge.
Make sure you are wearing a mask and eye protection during this step as flaking paint and plaster dust can become airborne.
When repainting, start by identifying whether the existing paint is oil-based or water-based. Check out How to tell between oil-based and water-based paint for an easy method of determining this. If it is oil-based, use oil-based primer and paint; if it is water-based, use water-based primer and paint.
Start with a sealer undercoat on any exposed plaster to help the new paint stick and prevent uneven finishes. Use a good quality ceiling paint in a flat or low-sheen finish so it blends with the rest of the room.
If you’re nervous about tackling it yourself, a heritage painter or plaster restorer could handle the prep work for you and leave the repainting to you.
Let me know what you think and if you have further questions, please don't hesitate to ask.
Jacob
