Different types of plaster dry at different rates. Some plasters dry within 90 minutes while others can take days to set: this depends on the room’s temperature, humidity, and ventilation. For thicker plaster or damp conditions, it could take up to four weeks before it’s ready for paint or wallpaper. 

As a rule, at JT Atkinson we’d recommend that you follow this guide:  

• Most plasters will set usually within one to three hours
• To fully dry though you should allow three to five days
• We'd recommend waiting two weeks or more before painting or wallpapering.

Dry plaster changes colour as it dries, going from dark brown to a pale, consistent pink. Run your hand gently across the surface—dry plaster should feel cool but not damp. If in doubt, wait a little longer to ensure it’s completely dry.

A few handy hacks: 

You can speed things up with a heater or by opening a window but try not to be tempted to paint your newly plastered walls too soon as the paint could crack and peel off.

Fresh plaster needs sealing before applying paint to prevent it from soaking in too quickly. Here’s how to prime plaster for a perfect finish:

1. Prepare the Surface: Ensure the plaster is smooth and free of dust or debris. Lightly sand rough patches if necessary. Rub the walls down completely with a damp cloth to remove any dust.
2. Mix a Mist Coat: Combine a watered-down emulsion paint (70% paint, 30% water) to create a thin, absorbent primer known as a mist coat.
3. Apply the Mist Coat: Use a roller for large areas or a brush for corners and edges. Let the coat dry completely before applying further paint.

One mist coat is usually sufficient, but for very porous plaster, a second mist coat may be needed. Ensure each coat dries thoroughly before adding more layers. The mist coat is very runny so it's a good idea to cover your floors and surfaces with a dust sheet and roll over and paint drips on your wall before they dry.

Once the mist coat is applied, you can paint your freshly plastered walls with standard emulsion.A few key pointers to set you on your way:

1. Choose the Right Paint: Use a breathable emulsion for the first layers to allow any residual moisture to escape.
2. Apply in Thin Layers: Start with one even coat and let it dry fully before adding another.
3. How Many Coats of Paint on New Plaster? Most walls will need two coats of paint for even coverage and a professional finish.

It’s open for debate, but depending on the quality of paint you’re using, you may be able to forego the mist coat. If you’re skipping it (which wouldn’t be our recommendation!), use a primer specifically designed for bare plaster. Apply it evenly and allow it to dry fully before painting.

After painting, it’s best to wait at least six weeks before drilling or hammering into newly plastered walls. For lightweight items, use adhesive strips that won’t damage the surface. For heavier items, use wall plugs and screws designed for plaster. If a mishap does happen and your new plaster gets cracked or has a hole appear, you can always patch it up without having to start the whole thing again.