Unstoppable

Cavity wall insulation for a multi-family building – Insute 25-pro as a high-performance problem solver

As part of a comprehensive refurbishment of a multi-family building in Flensburg, the premium blow-in insulation material Insute 25-pro was successfully used as a solution for cavity wall insulation. After replacing the windows with highly energy-efficient models, an imbalance occurred: the new, well-insulated windows contrasted with an uninsulated exterior wall. This increased the risk of condensation forming on colder wall surfaces, leading to a higher risk of mould growth. To restore the building’s physical balance, core insulation was essential.

Insulation despite extremely narrow cavities

The existing cavity in the façade was exceptionally narrow, measuring only 1.5–2.5 cm. Conventional blow-in insulation materials are typically approved only from cavity widths of around 4 cm and would not have been suitable.

Insute 25-pro, however, can be used from widths of 1 cm. The material distributes evenly within the masonry, reliably fills even the narrowest areas, and ensures safe and efficient cavity insulation without any change to the façade appearance.

The more economical alternative to complex measures

The only alternative would have been removing the outer wall layer and installing an external insulation system (ETICS). This solution would have been significantly more expensive and would have required major changes to the building’s appearance, including repositioning windows and altering light conditions.

By using Insute 25-pro, the insulation was implemented economically, with minimal impact on the building structure and without affecting its visual appearance.

Technically precise execution with verifiable results

A total of 18 m³ of material was injected through drill holes at joint intersections (where vertical and horizontal joints meet). Spacing ranged from 80–100 cm, closer in the base area and up to 2 m in wider wall sections.

An energy consultant confirmed the high quality of distribution using thermography: even in critical areas, the temperature difference was only around 2 °C - an indicator of homogeneous and complete filling.

The scaffolding used by the window installers could be utilized, as the insulation was part of a larger modernisation project.

Thermal conductivity of just 0.028 W/(m·K) – high insulation performance even at low thicknesses
Permanently water-repellent yet vapour-permeable
High thermal storage capacity – significantly higher than that of conventional insulation materials
Excellent sound-absorbing properties

The project impressively demonstrates how Insute 25-pro enables optimal, safe and cost-effective cavity wall insulation even under extreme conditions – thereby making a significant contribution to energy efficiency and quality of life.

Are you planning a similar project?

Whether it’s an older building, a historic structure, or an existing building with high energy efficiency requirements—we can assist you with the analysis, planning, and installation of modern blown-in insulation.