Screed for underfloor heating up

Screed for underfloor heating up

Who builds a house, is often under time pressure. A trade union is sitting the other in the neck and can only approach to work when previous work has been completed. But the builder itself would move as soon as possible. Finally, bearing down on him during construction a double burden. Building a house costs money, the bank would first installment or deployment interest and the rent for the previous residence must also be paid. Time is money.

However, one should not rush or break above the knee. Certain processes need their time. This includes the drying and curing of cast concrete parts, such as ceiling or floor, and the heating of heating screed.

Who does not scrupulously comply with the requirements herein and are the screed drying time or heating, can cause damage and, above all additional costs. Our information is intended to explain why the screed heating is necessary and help to avoid mistakes.

Summary: screed for underfloor heating up

  • Screed drying with or without underfloor heating
  • Why do I heat up the screed?
  • When do I heat up the screed?
  • How long do I have the floor to heat up?
  • What makes the screed heating program?
  • I need a heating protocol?

Screed drying with or without underfloor heating

When building a house next to CA screeds CT screeds (cement screed) come (Calziumsulfatestriche) mainly used. Their particular advantage lies in its good resistance to moisture and their suitability as a heated screed.

In the "desiccation" cement screed should be noted however that this does not dry to cure, but chemically sets. This means that is mounted screed needed moisture to cure completely. Only when the floor is walked on, which is usually achieved after 24 hours, allowed aired and excess water are removed. If previously the "dry" nachgeholfen, the screed can not harden properly, it gives rise to stresses and cracks.

Remember: keep it closed after the screed two Tage Fenster and doors or cover the screed with a foil. Can then be lifted and dried. Only after 21 days cement screed is fully cured and must be heated.

Why do I heat up the screed?

From physics classes each is still known for certain that stretch fabrics with heat and contract again in the cold. How much depends on the so-called coefficient of expansion. But so far we do not have to enter the subject.

Floor heating before the screedFloor heating before the screed

Like any substance also screed expands under heat. In the floor, however, the floor heating, which should be installed as widely as possible at the same distance though, never warms the screed evenly to 100% is. In addition, the screed sand or gravel contained in different grain sizes, which expand at different rates. All this ensures that tensions arise that can tear the screed.

Therefore, it is important to heat the cement floor slowly. The ingredients to get the opportunity to expand slowly and evenly and adapt to the environment. This tension can be compensated and reduced. After the screed was heated slowly after the heating-up, the material has adapted and can then also be heated quickly. The slow heating by floor heating is sort of a settling-in period - the "muscles" are stretched and warmed up. Only then they can be claimed correctly.

When do I heat up the screed?

On "When do I heat up the heated screed?" there is not any! When building a house, or the introduction of floor with underfloor heating, but the desire for a fast construction and the mandatory compliance with the heated screed drying time or curing meet.

Therefore, the question should not "When do I have ...?" rather "When can I ...?" ring. The question is relatively easy to answer - If the screed has hardened. this are given 21 days. Who is not under time pressure, can wait 28 days for safety. Then can you begin heating the cement screed. 

How long do I have the floor to heat up?

As the time required for curing of concrete is also prescribed heating the screed with underfloor heating. Speak of the functional heating.

The minimum layer thickness of screeds are specified in DIN 18560 and therefore differ in cement floors in a family house with typical stresses barely. In section, the heating tubes should covers approximately 45 mm, giving at at at a tube diameter of 15 to 20 mm, a thickness of the screed of 60 to 70 mm.

With various additives in the screed, the manufacturer may differ, but in principle the following applies heating program for screed:

Heating screed on floor heatingHeating screed on floor heating

  1. Flow temperature of 25 ° C heat up
  2. Flow temperature of hold 25 ° C
  3. Flow temperature of hold 25 ° C
  4. Flow temperature of 30 ° C heat up
  5. Flow temperature of 35 ° C heat up
  6. Flow temperature of heat up to 40 ° C
  7. Flow temperature of heat 45 ° C
  8. Flow temperature of heat up to 55 ° C
  9. Flow temperature of hold 55 ° C
  10. Flow temperature of hold 55 ° C
  11. Flow temperature of hold 55 ° C
  12. Flow temperature of Lower 45 ° C
  13. Flow temperature of Lower 35 ° C
  14. Flow temperature of Lower 25 ° C

When heating the screed, it is necessary to ventilate well. After the first 21 days to cure, although escapes already excess moisture until but being ready is reached, it may even take weeks for a few days up. of course crucial for heating screed dry season is the weather, the air and the moisture in the environment that is created by other masonry and plaster work.

For control of the maturity which is fixedly defined, depending on the flooring, a residual moisture measuring device should be used. This clearly shows how much moisture is still contained in the screed and whether a ground covering already may be laid.

What makes the screed heating program?

Since the screed thicknesses are always very similar, heating the screed in an underfloor heating system is almost always the same. Many heater manufacturers equip their heaters therefore with a heating program for screed, which is similar to the indicated time and temperature schedule or even look like that.

The automatic heating of heating screed has the advantage that one can no mistakes and the heater does not have to be adjusted manually every day. It is important, however, to consider whether the expiry of the heating program matches the information on the screed. If necessary, a consultation is necessary.

I need a heating protocol?

If you really need a heating protocol depends on your own work. Perform screed works and floor drying with radiant heating in-house from, you can customize a heating protocol for Although, in case of damage, but you can use it to make no claims for damages or warranty claims.

Without heating record any warranty claimsWithout heating record any warranty claims

The situation is different, however, if companies are involved in this work. Here is your proof a heating protocol that all deadlines for Estrichaushärtung and screed heat (duration, flow temperatures) or for heating screed drying time were met. It is therefore particularly important that is entered at every step, the date and confirmed. Only in this way can guarantee claims asserted if cracks occur in the screed after heating.

Contain the heating protocol should include the following points:

  • customer
  • Project
  • Construction stage (Stockwerg, individual rooms or building part)
  • Estricharbeiten executed (description, type of heating pavement ...)
  • Date protocol and overview of all the steps to the screed work and the heating program or a manual heating control
  • special Notes
  • Signature / stamp of the protocol leader Controller or the executing company

The heating protocol may be individually designed. But many companies already have their own templates and also refer to the Internet provides many examples that can be used and adapted.

Buy residual moisture meter online