A levelling plaster coat is the plaster layer that is drawn flat with a wide blade or straightedge immediately after application, creating a true, even substrate for a sprayed textured finish. In Dutch this layer is called a meslaag, from messen: levelling the still-fresh coat with a plastering blade.
Where it sits in the build-up
A plastered wall or ceiling consists of several layers:
- Primer or bonding coat — stops the substrate sucking too fast and secures adhesion
- Base coat (scratch/float coat) — fills irregularities and brings the wall up to thickness
- Levelling coat — applied thin and pulled flat; this layer determines the end result
- Finish — sprayed texture, decorative render, or trowelled smooth ready for paint or wallpaper
With a sprayed finish the substrate does not need to be mirror-smooth — the texture disguises small imperfections — but it does need to be flat. Bumps and hollows stay visible in raking light.
Practical tips
- Work wet on wet: do not start a new bay once the previous one has begun to set, or you will see the joins
- Check flatness with a straightedge of at least 2 m and look along the wall with a lamp (raking light) before spraying
- Keep the thickness even; plaster laid on too thick cracks and debonds
- Let the levelling coat dry and cure fully before spraying or painting; depending on thickness, temperature and ventilation this takes several days
- On a smooth, dense substrate (concrete, gypsum blocks) a bonding primer is essential
Related terms
- Plastering
- Base coat
- Fine plaster
- Spray texture
- Screeding off
- Levelling compound
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