repairing of hairline cracks on the plaster surface

A common phenomenon appearing mostly in old as well as new constructions. The reasons for hair-line cracks on the plaster surface vary. The main ones are the following:

  • Very thick application of plaster without the appropriate (or any) use of the special reinforcement fiberglass mesh.
  • Use of excessive quantity of water during the preparation of the mortar, changing its properties.
  • Use of excessive quantity of water during the sanding (finishing) of the plaster surface.
  • Fast drying of plaster surface after finishing because of high temperatures or strong winds.

The repair of these hairline cracks is necessary for a construction, because apart from changing the appearance of the plaster, it can also become the source of moisture penetrating into the masonry.

episkTrixoeidonTo repair the problem we can use the following materials:

Elastoplastic sealing acrylic putty


  • Hair-line cracks are opened at a 2-3mm width with the help of a spatula or cutter.
  • Dust is removed with a brush or air.
  • The ACRYL-FIX ampoule nozzle is cut slant-wise with a knife, so it sits on the crack’s edges.
  • The acrylic putty is applied by holding the ampoule at a 45°angle to the crack.
  • While the putty is still fresh, its surface is smoothened with a spatula.
  • After it dries, the repaired surface may be painted directly.