Screeds

Screeds

Basic characteristics

Consistency – mobility

Determining the consistency of fresh mortar for self-leveling screed is done by using a measuring cup beaker with a capacity of 1.3 liters. A solution is poured into the measuring cup beaker, which is placed on a flat surface. Then the container is lifted and the contents in it should be poured evenly till the circle has a diameter of 38-43 cm.

 

Tensile and compressive strength

  • 20 N/mm² under PVC coating
  • 10 N/mm² under laminate
  • 8-10 N/mm² under ceramic flooring

 

Adhesion – the bond between the screed and the base

 

Screed thickness

From 20 to 150 mm, depending on:

  • Iregularities on the base
  • The method of application
  • The necessary strength and curing time
  • The type of coating and the type of building
  • The presence of installations (electricity, water supply, underfloor heating, etc.)
  • The presence of reinforcement, with thicker screeds

Curing time

On average, screed curing time is 24 hours. The faster the process of reaching sufficient strength, the shorter the period of use is.

 

Moisture of the screed

The residual moisture content of the screed is checked with a sample which is 4 cm in height. The sample is smoothed and allowed to dry with the screed that is laid in the room. Then the sample is torn to pieces and 20 grams of it is weighed. After that it is crushed and placed in a special flask with metal balls. Finally, the flask with metal balls is shaken vigorously. There is a manometer on the container for direct reading of the humidity of the materials. Wait until the required humidity is reached, depending on the coating.