How long does plaster take to dry?

Fresh plaster goes through a colour change as it dries — from a wet dark pink, through a patchy two-tone, to a uniform pale pink. That uniform pale colour is your sign that it's properly dry.

As a rough rule: a skim coat dries in 3–7 days in normal household conditions. Backing coats on a full re-plaster can take 7–14 days. Render takes longer, especially in cold or damp weather — sometimes 3–4 weeks before it's fully dry.

Don't rush it. Painting plaster that isn't fully dry traps moisture, which causes peeling paint and patchy finishes. Use a mist coat (watered-down emulsion, around 70/30) for the first coat to let the wall keep breathing as it finishes drying.

Speed it up sensibly with gentle warmth and airflow — open a window, leave the heating on a low background level. Avoid blasting it with a dehumidifier or fan heater on day one as that can cause cracking.