Interior plaster crumbles - what to do?

If the plaster crumbles from the wall, that is not necessarily a case for the expert. As a Do-It-Your-Self home improvement, you can easily repair holes and cracks yourself. We'll tell you how to do that.

Why is the interior plaster crumbling off the wall?

Especially in old buildings, the plaster has its best times behind. When you pull off old wallpaper, it happens that all the same pieces of plaster go with it. Drill holes and cracks do the rest.

If the wall is to be repainted later or wallpapered, a renovation of the damaged areas is inevitable. Smaller cracks or holes can be filled with a putty, with larger damage, it helps only to renovate the interior plaster.

So go ahead

Before it starts to apply the interior plaster, the substrate must be prepared. The wall must be clean and stable. Loose plaster parts must be knocked down to the masonry. Carefully tap the rest of the wall for voids.

In order for the new interior plaster to last well, you need a primer. Particularly absorbent substrates should be pretreated with a deep foundation.

Which work materials are needed?

  • Finished plaster mixture
  • Mortar vat to prepare the mixture
  • Drilling machine with mortar whisk
  • Spatula, trowels
  • Pulling board, stripper

How is the plaster applied?

Always apply the plaster from bottom to top. If the plaster layer is thicker than 15 mm it is recommended to plaster in two layers. For in-wall applications, a larger grain size of 2 to 4 mm can be selected, for the top coat 1 to 2 mm.

Apply the finishing plaster only after the concealed plaster has dried. Larger surfaces are smoothed with a leveler or with a wooden float, by gently pushing the watered board over the wall in a circular motion.

If a corner must be plastered, a planed board is struck laterally. Once the plaster has dried, it comes to the other side and the plaster connection on the corner can be executed perfectly. Also helpful are steel or plastic edges, which are plastered with.

Tips & Tricks

At the transition points to the old plaster a joint tape or a crack bridge should be plastered with. This prevents a later cracking at the crossing points.

Product Image: Anna Antonyshyn / Shutterstock

Video Board: Repairing a crumbling plaster wall