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Interior sealing



If the humid walls are not accessible from the outside, as, for example,
in the case of superstructures, our professional interior sealing presents
a valuable alternative. It reliably prevents, just like our exterior sealing,
the penetration of water into the interior of the building.

Interior sealing

The problem: Lateral moisture penetration

If the exterior sealing is damaged or even lacking, moisture penetrates laterally into the masonry through the area in direct contact with the ground. Our interior sealing is the perfect solution if exterior sanitation is impossible or too laborious.

Our 1st step: Preparation/Plastering

We expose and thoroughly clean the masonry that needs to be sealed, and create a groove and a concave moulding in the junction between wall and floor. We then apply our ISOTEC Sealing Plaster. The plaster ensures ideal adhesion and an even spreading of the following sealing layer.

Our 2nd step: Sealing

We apply our ISOTEC Sealing Mud in two steps. This flexible material presents the actual sealing layer. It is waterproof, seals cracks and permanently protects the surface of walls against moisture.

Our 3rd step: Insulation/Protection

Depending on the object and the client´s necessity, we either apply a vapour-permeable plaster or an interior insulation system for the protection of the sealing. The interior insulation ensure a pleasant indoor climate as well as energy savings.


Our ISOTEC Interior Sealing has been examined according to the regulations of the WTA (German scientific-technical consortium for the preservation of buildings and monuments). The Material Testing Office of North Rhine-Westphalia certified its impermeability under a water pressure of 0.75 bar (7.5 m water column).

Your benefits at a glance

  • Solutions for details (penetrations of pipes, cross walls, junctions

  • Energy savings, if the interior insulation has been applied for protection purposes

  • Permanent moisture protection from the inside

  • Pleasant indoor climate after sanitation

  • Conservation of property value

Interior sealing: Our references

Private home with holiday flat

The ISOTEC Group has successfully sealed more than 100.000 properties in Germany, Austria and Switzerland in the last 25 years.

Our sanitation of the cellar has been another milestone in the history of this building, constructed in 1930. Thanks to our ISOTEC Interior Sealing, we converted the once uncomfortable and humid cellar into a pleasant living space, which offers enough room for a wine cellar.

Accuracy is the road to success

At first we check whether the affected cellar walls are suitable for our sealing measures. If this is the case, thorough preparation of the substrate and the use of materials particularly developed and tested for this purpose will guarantee a successful and permanent sealing.

Interior sealing

Complementary measures

Apart from our interior sealing, further measures might be necessary in order to reliably prevent the expansion of moisture within the building. In those cases, we offer approved solutions that can be specifically adapted to your requirements. Our ISOTEC Paraffin Injection, for example, prevents the capillary expansion of moisture to adjacent floors and walls.

Downloads interior sealing