If you’re getting ready to paint or renovate your interior walls, plastering is an essential first step. But rushing the paint job before the plaster has dried can lead to bubbling, peeling, or a poor finish. In this post, we’ll answer the common homeowner question: how long does plastering take to dry, especially in New Zealand’s changing climate. We’ll also address whether you can plaster over old paint, and share tips for a smooth, professional result.

How Long Does Plastering Take to Dry in New Zealand?

The drying time for plaster depends on the type of application and environmental conditions.

  • A thin skim coat of plaster (typically used to smooth existing surfaces) usually dries within 2 to 3 days.
  • A standard single-layer plaster job on new walls generally takes 4 to 7 days to dry fully.
  • If multiple layers or thick coats of plaster are applied, drying may take anywhere from 7 to 10+ days, particularly in colder or more humid areas like Wellington or Lower Hutt.

Pro Tip: How to Know When It’s Dry

  • Colour test: Wet plaster is dark brown or pink. When it turns a light, chalky beige, it’s dry.
  • Touch test: Press the wall gently-if it feels cold or damp, it needs more time.

Don’t apply primer or paint before the plaster has fully dried, as this traps moisture and ruins the finish.

Can I Plaster Over Old Paint?

Yes, you can plaster over old paint, but it’s critical to prepare the surface correctly.

Here’s how:

  1. Clean the painted wall to remove grease or dust.
  2. Sand the surface to create a rough texture for adhesion.
  3. Apply a bonding agent like PVA to help the new plaster stick.
  4. Ensure the old paint isn’t peeling-otherwise remove it entirely before plastering.

Skipping any of these steps may cause the new plaster to crack or fall off prematurely.

When Can I Paint After Plastering?

Once the plaster is dry (minimum 4-7 days for single coats), you can apply a primer followed by your chosen paint. Avoid painting too soon even if the surface “feels” dry because internal moisture may still be present.

DIY vs Professional Plastering: Why It Matters for Drying

DIYers may apply uneven layers, leading to extended drying times. Professional plasterers use the right mix ratios and finishing tools that allow for faster and more consistent drying.

If you’re in a hurry to complete a home makeover or prep for painting, hiring a pro saves time and avoids costly rework.

Final Tips & Summary:

  • Allow at least 4–7 days for plaster to dry before painting.
  • For thicker layers, drying could take up to 10 days.
  • You can plaster over old paint, but surface prep is key.
  • Never paint over damp plaster, it leads to long-term wall damage.
  • Always assess climate and airflow when scheduling plastering jobs.

Need professional help with plastering or painting? Our expert team at RE Decorators ensures smooth finishes, proper drying times, and wall prep that lasts.