Insulate a wall against moisture and cold


Walls must be insulated or insulated against three influences. Damming is primarily aimed at sound and temperature transmission. When insulating a wall is primarily realized protection against moisture and moisture. Moisture and temperature insulation usually interact and influence each other.

Moisture, cold and sound

Moisture and moisture in the wall arise in several ways. They can penetrate into the masonry from the outside or rise from the ground in the wall. Condensation can form from the inside if temperature differences to the outside lead to different humidity levels.

Accordingly, when isolating the wall, each of the influencing factors must be considered. The problem may be that the insulation effects are functionally contradictory. A typical example is the Styrofoam airtight insulated against cold wall, which gets wet through condensing "sweating".

Assessment and planning of isolation

For the execution of a wall insulation many insulating materials and different construction and mounting types are considered. In general, the following structural conditions and parameters must be checked:

  • Moist walls must be rehabilitated
  • Existence of large temperature differences in the wall (outer walls)
  • Are there any potential cold spots (windows, frames, stringers, connecting walls)?
  • Is sealed from the outside or from the inside
  • Are sources of moisture expected from indoor areas (bathroom, kitchen, laundry)
  • If a simultaneous sound insulation, for example, to the neighbors
  • Space and space limitations are available for insulation
  • If the insulating material is filled in cavities or mounted in plate form
  • Fire protection requirements must be observed

Properties of insulating and insulating materials

The most common insulation materials have the following properties:

insulationthermal insulation effectmoisture-proofingdiffusion
Styrofoam / Styrodurhighhighnone
mineral woolhighmediumavailable
Vapor barrier filmnonehighnone
fiber insulation boardshighhighavailable
rigid foamhigh to very highmediumnone
cellulosehighmedium to lowavailable
hemphighmediumavailable
Plate foam glasshighhighnone
Crushed foam glassmediummediumavailable
mineral blockshighhighnone
Calcium silicate boardsmediumhighavailable
corkmedium to highmedium to highavailable

Block diffusion in the right place

Isolation often has to be weighed due to structural factors. The selection of the insulating material always depends on the wall condition. Decisive for exterior walls is the correct placement of a possibly inevitable vapor barrier film.

If an ecologically oriented insulation is desired and a wall of diffusible building material, should be dispensed with any diffusion closure. Constructions with ventilation and inspection openings can drain the wall again and again if continuous diffusion is present.

Each wall insulation can be influenced by material thicknesses and combined use of several substances in composite systems. Supplementary nonwovens and cavities can compensate, for example, in ventilated combination systems, the respective weaknesses and strengths of the selected insulation materials.

Tips & Tricks

The decisive factor for your insulation goal is the heat transfer coefficient. It is also referred to as a U-value. Before any isolation, you can use computers provided on the Internet to check the U-values ​​of the candidate materials.

Artikelbild: Alis Photo / Shutterstock


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