ᐅ Disadvantages of Fast-Drying Screed?

Hello everyone,
we were supposed to receive standard screed today because we wanted to avoid the extra cost of fast-drying screed and we are not in a rush. Now the contractor cannot come due to problems on another site and seemed very apologetic. As compensation, he is offering to install fast-drying screed at no additional cost.
Are there any disadvantages to fast-drying screed, or should we accept the offer?

One of the three tilers I had for an inspection, but ultimately did not hire (though not for this reason), said he never uses fast-drying screed because it’s less durable and tends to crack or even crumble. I can’t say how true that is; our showers were installed with fast-drying screed sloped to drain, and after three years of use (mainly just one shower), you can’t notice any issues. Of course, any problems could be hidden beneath the tiles. I think it depends on proper mixing.

The additives that make the screed dry faster don’t speed up the curing process themselves but reduce the amount of water needed. In other words, water that would normally be added but then evaporates without contributing to curing isn’t added at all in this case.

This makes thorough mixing even more important so that the water actually required for curing reaches every part where it’s needed. But professionals should usually be able to manage this properly.

Tolentino schrieb:

The additives that make the screed "dry faster" don’t actually speed up the setting process or anything like that,

That is not entirely correct. Additives primarily ensure
- faster hydration (chemical binding of the water)
- better flow behavior, which also means slightly less mixing water is needed
- partial improvement of the structure, allowing moisture to escape more quickly
- faster achievement of final strength

bauambach2025 schrieb:

Are there any disadvantages to fast-drying screed?

If installed correctly, there is only one disadvantage, which doesn’t apply to you: the cost.
Be happy that the construction time is significantly reduced, you can move into your house sooner, and you will save electricity on the function/warranty heating because it all happens faster.

P.S. My own screed was ready for covering after just a few days. It didn’t curl at all and was perfect for laying parquet flooring.

Then either there are differences, or my expert was wrong.

Tolentino schrieb:

Then either there are different types or my expert gave incorrect information.

Incorrect. The mode of action is the same for all screed accelerators. You can verify this with manufacturers, installers, and even AI (LOL).

Or explained in more detail for professional users: