Cellulose insulation is a natural insulation material manufactured from recycled newspaper and cardboard. The material is shredded into loose fibres, treated with fire retardants and fungicides, and used as an effective thermal insulation in walls, floors, and roofs.
Composition and production
Cellulose insulation consists of approximately 80 to 85 percent recycled paper. The remaining 15 to 20 percent comprises additives such as borate salts and boric acid. These additives make the material fire-retardant, mould-resistant, and unattractive to pests.
The manufacturing process is relatively simple and energy-efficient. Compared to the production of mineral wool or synthetic insulation materials, cellulose insulation requires significantly less energy to produce, making it one of the more environmentally friendly options available.
The material can be installed using three methods: dry-blown into enclosed cavities, wet-sprayed onto open wall or ceiling frames, or loose-filled onto horizontal surfaces such as attic floors.
Application
Cellulose insulation is widely used in both new construction and renovation projects. It is particularly well-suited for retrofitting existing cavity walls and roof structures, as it can be introduced through small injection holes without the need for extensive demolition work.
The thermal conductivity (lambda value) typically ranges from 0.038 to 0.040 W/mK, comparable to standard insulation materials such as glass wool and stone wool. An additional benefit is its excellent moisture-regulating capacity: cellulose can absorb and release moisture without significant loss of insulation performance.
Related terms
- Blown-in insulation
- Thermal insulation
- Sustainable building
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