Plaster a wall heating system with lime plaster

There are different plasters. But the use of wall heating places special demands on the plaster. Not every plaster is equally suitable. One of the plasters that are preferably used for wall heating is lime plaster.

The general structure of a wall heating system

The wall heating is preferably installed inside the outside wall. There should be very good insulation behind the wall heating (either internal insulation of the external wall or facade insulation such as ETICS). The wall heating itself is then covered. Either the
Wall heating clad in dry construction or just plastered. The main plasters that are used would be:

  • Also read - Installing a wall heater
  • Also read - wall heating electrical flush-mounted
  • Also read - installing a wall heater
  • Cement plasters
  • Gypsum plasters
  • Lime plasters
  • Clay plasters

Basics about plaster: layer thickness and structure

First of all, it should be noted that the maximum plaster thickness should not exceed 30 mm. The plaster base in which the wall heating is plastered should be a maximum of 10 to 15 mm. Plasters with a high cement content (more than one percent) are not well suited, as these plasters tend to have a high tendency to crack due to the thermal effects.

Instead, lime or lime plaster plasters are often used. However, the requirements for the plaster as well as the requirements for wall heating in plaster must be taken into account here. Lime plasters should set as slowly as possible.

Pay attention to the thermal expansion of the pipes when plastering

However, the wall heating must be turned on briefly when it is freshly plastered. The heating pipes experience thermal expansion. In the case of a young plaster that has not yet set, the pipe can expand and this expansion is retained in the plaster. Thermal stress cracks can therefore only occur to a limited extent later.

Lime plasters, however, have to set slowly

With lime plasters, it is therefore important how the heating is retracted. During plastering, the wall heating should therefore be briefly turned on and then switched off again. If the wall heating consists of several registers that form independent heating circuits, you can plaster area by area and make the necessary expansion of the heating coil.

Please note if reinforcements are required: Lime plasters are alkaline

If you want to use a reinforcement in the lime plaster, you must also consider its chemical characteristics. Lime plasters are alkaline. Many plaster reinforcements such as fiberglass mats then have to be alkaline-resistant. Be sure to pay attention to this when choosing the fiberglass mats.

Tips & Tricks A plaster that is particularly suitable for wall heating is clay plaster. Those who find the processing of clay plaster so demanding can now fall back on solutions from drywall construction with clay. Tips & Tricks Clay building boards are also available as dry building boards. These are very well suited for old buildings where moisture regulation is also carried out. Clay plasters in the form of clay building boards have proven themselves so well that they are even used in modern energy-saving houses.