Flexible Natural Insulation for Timber Joists, Rafters & Wall Studs

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Flexible insulations like Indibreathe Flex (hemp and jute), Gutex Thermoflex wood fibre, Cosywool (sheep wool) and Grammitherm grass insulation offer a simple, effective way to improve thermal and acoustic performance in timber-framed walls, floors, roofs and ceilings. Each fits snugly between studs, joists and rafters, delivering excellent energy efficiency and a healthier internal environment.

Flexible insulation made from natural fibres help regulate temperature and humidity while reducing a building’s overall environmental footprint. Their breathable nature allow moisture to diffuse safely, helping to avoid condensation and mould, especially important in older buildings or those with timber structures.

All our fibrous insulation is easy to cut with an insulation saw and easy to install thanks to the flexible structure that ensures a tight friction fit between uneven joists or wall studs. It stays securely in place without slumping, helping maintain consistent thermal performance over time. It also provides effective soundproofing, enhancing comfort in both residential and commercial settings.

Whether you're upgrading an existing property or building from new, Indibreath Flex, Thermoflex, Cosywool and Grammitherm offer an eco-friendly, high-performance insulation solution that works in harmony with the building fabric.

Flexible Insulation

Natural, flexible insulation is designed to fit snugly between timber studs, joists and rafters. Unlike rigid insulation, it adapts to small irregularities in framing, ensuring a tight fit that reduces air gaps and thermal bridging. The material is highly breathable, allowing moisture to diffuse safely through the building envelope and reducing the risk of interstitial condensation.

Its high thermal mass also helps buffer indoor temperatures year-round, keeping spaces warmer in winter and cooler in summer. The insulation remains stable over time and doesn’t slump, making it ideal for use in walls, roofs, floors, and internal partitions.

Gutex Thermoflex delivers breathable, high-performance insulation for walls, roofs, and floors. Its flexible wood fibre composition ensures a snug fit between timber joists or studs, reducing heat loss and noise transmission. It is safe to handle, eco-friendly, and ideal for use in natural or low-carbon construction projects. With excellent thermal and acoustic properties, it supports healthier indoor environments while simplifying the installation process.