Anhydrite screed: what disadvantages does it have?

When it comes to choosing the right screed, many are often at a loss. Anhydrite screed is ecological, and offers some benefits to the user. Anhydrite screed also brings with it some disadvantages that should always be considered. Which are these, read here.

Composition and properties of anhydrite screed

Anhydrite is a precursor of gypsum. Due to this fact, the anhydrite screed behaves like many gypsum substances. This includes, above all, a high moisture sensitivity.

Binder is CA cement screed (calcium sulfate screed) is not cement, but anhydride. As a result, anhydride screed also has significantly different properties in some areas than a cement-based screed.

For the Feuchtbe

properties

If anhydrite comes into contact with water, it may swell and be damaged in the process. In high humidity, the screed not only discolor and swell, but also tends to fungus. There is a high risk here.

A use in damp rooms or in case of potential humidity is therefore not recommended. That's the case in rooms like:

  • bathrooms
  • toilets
  • Waschkuüchen
  • basements

As a heating screed anhydrite screed is very good as high-quality use. It has a high heat storage capacity and gives off heat very evenly.

drying times

Unlike other types of screed, CA screed or anhydride hardens very quickly. While you often have to wait for cement screeds up to 30 days to apply a Bodenlag, this period is anhydride screed in only about 7 days.
For even faster curing, an Anhdrid screed can even be dried just a few hours after insertion using a condenser dryer. The curing then goes in no time.

Cement screed, on the other hand, has a drying time of 20 to 30 days. This is one of the essential many differences to other types of screed.

resistance

Compared to other types of screed anhydride Esrich shows little resistance. It is not suitable for heavily loaded areas.

Post processing and effort

Anhydrite screed is more time-consuming to lay and also requires an elaborate reworking: The floor must be completely sanded so that a floor covering will find support on it. That also leads to that

Tips & Tricks

In an environment where high stress is required, and in all rooms where water or moisture play a role, a different screed should be used better.

Video Board: Solutions for Tiling to Anhydrite Screeds