A move that comes at a delicate moment for the European market of insulation materials: ISOVER (Saint-Gobain) expands its range with new interlocking felts designed for thermal insulation of wooden structures and dry construction systems. The manufacturer's strategy aims to consolidate its presence in the segment of flexible and rapid installation, a sector that according to industry data represents approximately 35% of the residential market for insulation systems in mineral wool in the DACH area.
The new felts position themselves as a technical alternative to traditional rolls, offering installers a pre-cut solution for standard cavities between wooden studs or metal profiles. The interlocking technology — based on elastic compression of the material — allows installation without thermal joints and reduces site installation times by an average of 20-25% compared to mineral wool rolls, according to ISOVER. The declared λ (lambda) value ranges between 0.032 and 0.035 W/(m·K), in line with market standards for glass wool of class WLG 032-035 according to DIN EN 13162.
The innovation should also be read in the context of the recent closure of fiberglass production in Bergisch Gladbach, announced by ISOVER as part of a rationalization of European production capacities. The Saint-Gobain group has stated its intention to concentrate investments on higher value-added products and with improved sustainability criteria, in line with the growing demand for Environmental Product Declarations (EPD) in public projects and DGNB or Passivhaus certifications.
From a regulatory standpoint, interlocking felts must meet minimum fire reaction requirements (class A1 or A2-s1, d0 according to EN 13501-1) and guarantee dimensional stability for operating temperatures up to +250 °C in applications near flues or building service penetrations. For designers and site managers, the choice between felt and roll depends mainly on cavity geometry and the frequency of structural elements: regular cavities with 62.5 cm spacing favor pre-cut felt, while variable geometries or retrofit applications require more flexible solutions.
ISOVER has not disclosed details on list prices or production capacity dedicated to the new products. The launch fits into a European insulation materials market that, according to EUROSTAT, recorded a 12% contraction in volume in 2023, mainly due to the decline in new residential construction in Germany and France. The growing regulatory pressure on recycled material content and carbon footprint — strengthened by the EPBD IV directive — could accelerate product differentiation towards certified and traceable solutions throughout the entire supply chain.
