Properly process the source mortar and fill in joints or cavities

Most mortars, especially with cement content shrink and shrink during drying and setting. In some cases, this property develops the exact opposite of the intended use. When proper processing of swelling mortar voids fill as desired by expanding the material.

Sources shrink instead

Conventional mortars bind by evaporating the water contained. During this process, the volume shrinks by at least the water content. For many jointing mortars this creates the usual and desired height difference to the surrounding tiles, slabs or stones.

When mortar is used to fill cavities or create even joints, shrinkage and shrinkage is disadvantageous. In these cases, a source mortar is introduced. Special aggregates cause the mortar to swell up to ten percent of its volume during setting.

Processing and conditions

The basic mixing ratio of the mortar is similar to conventional mortar. When calculating the amount of use, sufficient space must be given, especially in cavities of the volume expansion.

Spreading mortar has a reduced pot and processing time. They should be processed after mixing in a maximum of 15 minutes. In order to develop their swelling property specifically and to the required extent, the following external conditions are required:

  • Use clean drinking water for mixing
  • Avoid direct sunlight
  • Do not mix with lime hydrate, use only pure cement mortar
  • Only work during calm
  • Processing temperatures outside as possible between ten and twenty degrees Celsius

Control and extend duration of setting

If the setting process "overtakes" the swelling, the setting can be adjusted by subsequently drenching the mortar. Too fast drying produces hard and rigid surfaces that have not yet expanded in the available space.

To save the source mortar too fast loss of water, soaking and moisture absorbing substrates are also wet. During the processing and the swelling process, remove the protruding mortar promptly with a trowel, wet it and smooth it out of joints.

Tips & Tricks

With offers for Quellmörtel find the product indication that it is used for positive stuffing and filling. This feature is a building physics prerequisite, especially for wall elements in column construction and prefabricated house walls, which you must fulfill.

Artikelbild: Miriam Doerr Martin Frommherz / Shutterstock

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