Plastering of interior ceiling using gypsum mix Knauf G\F Leicht

The plastering works are carried out with the new German PFT-G5 equipment. The team of workers consists of 3-4 highly qualified persons. One team plasters approximately 30-50 sq. m of ceiling in one business day.

MP75 G/F Leicht is a gypsum-lime plaster mixture. Usually used for single-layer plastering of internal heated-cooled ceiling in the Lithuanian market.

Benefits and advantages:

  • The mix weighs less than other MP75 plaster mixtures.
  • A single high quality filling of walls is sufficient for painting the plastered walls.
  • The mixture has good yield, it is elastic.
  • It is possible to get a decorative texture (not possible with other Knauf gypsum mixtures).
  • Unlike other gypsum plasters, this plaster can be used for single-layer plastering of indoor heated-cooled ceiling.
Mix described in article

Plastering process

Prior to plastering the ceiling it is necessary to insure that the surfaces are primed.

Insufficiently absorbent or non-absorbent surface of concrete is primed with “Knauf Betokontakt” primer

In other cases, when plastering on gypsum boards, the surface is primed with “Knauf Putzgrund” primer

When plastering with “MP75-G/F Leicht” plaster the average layer is 8 mm to 12 mm. When a thick layer of plaster is required, plastering is done in two stages. After plastering the ceiling, carpets of capillary tubes is installed there. (see

The second layer of plaster “MP75 G\F Leicht” is to be sprayed before the first layer dries.

A fine pattern texture or smooth ceiling can be created using moistened sponges; the ceiling is almost ready to be painted (after coating once)

Plastering using “Knauf” technology results in a ceiling suitable for all Your needs.

If the air temperature exceeds 10 C°, heating is allowed immediately after plastering. In this case the water temperature in the carpet of capillary tubes must be at least 25 °C for three days. After that the temperature in the tubes is increased to 50 °C and maintained for 4 days. After that the heating can be turned off, however the plastered planes must be protected against too rapid cooling or cross-wind.

Comparison of technical specifications

Material MP-75 (plaster) MP-75L (plaster) MP-75 Diamant (plaster) KZ Maschinenputz (lime mortar) Common Lithuanian lime plaster mortar
Flexural strength in tension
Compressive strength
Water vapor diffusion resistance factor
Thermal conductivity capacity
Consumption of material for 1 m2 when the thickness of the plaster layer is 1 cm
10,5 kg
8 kg
12 kg
15 kg
16 kg

Useful tips

In winter, the amount of water vapor in the air indoors is greater than outdoors. Due to the difference in pressure, the warmer water vapor tries to move from the inside to the outside. This is called water vapor diffusion, or, in spoken language, “plaster breathing”. Depending on the plaster mix used, the diffusing water vapor meets certain resistance (μ). The greater the water vapor diffusion resistance factor, the slower the water vapor diffusion through the material.

Thermal conductivity is the capacity of the material to transfer heat, i.e. the thermal insulation of the material. This feature is described by the thermal conductivity coefficient λ (expressed in W/mK). The lower the λ value, the better the insulating properties of the material. It must be noted that MP-75 gypsum plaster has excellent thermal conductivity properties (0.35 W/mK). Thus, the smaller the coefficient λ, the smaller the heat loss.