Some of the areas that will require interior preparation are: Plaster, Dry Wall/Plaster Board, and Fibro sheeting all have similar characteristics when it comes to preparing for painting. Whether the materials are new, or you are repainting the surfaces, the preparation is similar. If repainting fibro it is best to err on the side of caution in case the fibro contains asbestos.
If the surface is new it is easiest to apply an undercoat or sealer to the surface as that will make it easier to see any blemishes that may require attention and minor rectification work. Once you have applied that coat then you can follow the same process as if the job is a repaint.
If repainting the surface you need to find out what paint type you are over coating, (have a look at our Test Paint Type page to find out how to determine if an undercoat is needed), an adhesion test to ensure that you are applying your new paint to a sound surface. (At the same time you can also do a Lead Paint test, it is easier to do the test once you have cut through the surface while doing the adhesion test.) If the surface passes the adhesion test then you can be confident to start doing the preparation work.
Check for gaps and cracks around door frames, window frames and other trimmed areas and fill with an acrylic caulk or gapping compound (check that the compound you use is paintable as there are some silicon based product that paint won’t adhere to).
For holes and cracks in the surface a filling compound should be used, whether a premixed or powder filler you mix yourself, either will suffice. For minor repairs that only require one coat of filler use one that is suitable for sanding. For larger cracks and holes use a faster drying compound which will be harder to sand, and then over coat it with the easily sand-able filler).
Once all fillers are dry you will need to sand them. I suggest you use fine grade sand paper or fine grade foam sanding block.
Then spot prime/undercoat the plaster filled areas.
Now you can start on your painting project.