Joint Sealing System

Choose the Hanno 3-Layer Joint Sealing System to gain protection against warranty claims: when the HANNO system components are used for all layers, we offer you a property-related functional guarantee of 15 years.

Impress your customers by helping them lower their heating costs and proving long-term quality sealing.

The Hanno 3-Layer Joint Sealing System gives your windows a tested* joint seal suitable for passive houses.

> More information on our passive house study

Joint Sealing System
BIM Daten von HANNO



+49 (0) 5102 7000-0


3-Layer Joint Sealing System Product Properties

• Temperature factor fRsi 0.92 to 0.96
• Good air-tightness
• Very good thermal insulation


What is a sealing system?

Different sealing systems can improve energy efficiency inside buildings. They can be used to seal masonry joints or window joints, for instance, and prevent penetration by wind and rain. They also facilitate a controlled exchange of air between indoor and outdoor areas. This helps create a comfortable indoor climate and optimise energy costs. HANNO offers a broad range of sealing systems. We offer joint sealing tapes, flashing tapes, multi-functional tapes, sealants and sealing foams that fulfil different requirements.


Construction requirements for sealing systems

Sealing systems face high demands when used in construction applications. These are intended to prevent an uncontrolled exchange of air between heated rooms and outside, and wind and moisture from penetrating the construction from outside as a result of driving rain. At the same time, it is important to ensure that any moisture that arises in the window joint (e.g. construction moisture) can diffuse to outside and be transported away. Seals must offer a long service life and fulfil their purpose for many years to come.


Sealing systems in construction: The 3-level model

We differentiate between three different sealing system layers to fulfil these sealing system requirements.

The three levels are as follows:

  • Level 1: Separation of interior and exterior climate
    In accordance with DIN 4108-2, joint transmission coefficient a ≤ 0,1 m³/ [mh (daPa)2/3] applies for the requirement of component and component connection joints.
    Undefined air flows are prevented by a carefully designed air tightness level. Draughts, ventilation air losses, condensation in the construction and connections, and water transportation processes are minimised.
  • Level 2: Functional area
    The requirements of thermal insulation, sound insulation and load transfer in particular must be ensured in this area. In order to ensure that these requirements are met in the long term, this area must be guaranteed to remain dry.
  • Level 3: Weather protection level
    The greatest water loads occur on the outside of the joint due to rain, driving rain and rain water run-off. Defects in the exterior sealing, tears in the edges or cracks in the construction material cause water to enter the joint. Capillary joints measuring just a few tenths of a millimetre are particularly problematic. Wind forces increase water transportation. The requirement for the exterior sealing level is thus permanent protection against external effects, especially driving rain and wind. The all-round seal is intended to prevent rain water (driving rain) from penetrating the joint. Any moisture that does penetrate must be discharged to outside in a controlled way.


It must be certified that water vapour diffusion does not lead to any impermissible concentration of moisture in the joint area (component-joint-wall). This can be ensured by applying and executing the principle of “tighter inside than outside” in relation to the water vapour diffusion of the overall system.

HANNO sealing systems for façade construction

The primary purpose of sealing systems used in façade construction is to seal joints in the masonry and between different façade elements. Sealing systems used in this area need to be long-lasting and able to be painted over and installed quickly and in large quantities. HANNO offers sealing tapes with good recovery properties and good thermal and sound insulation to meet these specific requirements. Because we offer long roll lengths, tapes can be installed quickly. Other requirements for sealing systems used in façade construction include good resistance to driving rain, air tightness, air permeability, good recovery properties, weather resistance and fulfilling strict fire protection provisions. Specialised fire protection tapes are flame retardant and can be used, for instance, in partition walls and fire protection doors.

HANNO sealing systems for window construction

The joint between a window and masonry component is a weak point in window construction. The result is joints that need to be properly sealed in order to prevent damage to the construction or valuable energy being wasted. Incorrectly sealed joints cause moisture damage such as mould and can necessitate expensive rectification work. Interior areas are hotter or colder than the exterior air depending on the season and on whether air conditioning systems are used. In all cases, it must be ensured that the transported moisture does not cause damage to the construction as a result of the installation joint.

1. Weather protection layer

This layer needs to keep out wind and driving rain, but also be vapour-permeable.

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2. Functional layer

This layer is between the internal and external seal, and is used to produce sound and thermal insulation in connection areas. It must be filled completely.

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3. Interior layer

This layer needs to be air-tight and offer a higher level of resistance to vapour pressure than the outside seal. Products tested for moisture variability are an excellent way to achieve this combination.

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