cellulose insulation is a material known for its high density. While this property naturally gives it superior thermal performance, it can raise questions about the strength of ceilings when cellulose insulation blown into attic spaces. What is the situation?
A technical challenge that is often underestimated
When it comes to insulating unused attic space, the issue is not limited to the thermal performance of the insulation. The mechanical strength of the ceilingsupporting the insulation is just as crucial. Too often, homeowners and professionals alike are reluctant to opt for cellulose insulation, fearing excessive load or risk of deformation. However, studies conducted by theECIMA (European Cellulose Insulation Manufacturers Association) show that this bio-based insulation is perfectly compatible with plasterboard ceilings, provided that current standards are met.
cellulose insulation a high-performance, sustainable bio-based insulation material
Made from recycled newspapers, cellulose insulation France cellulose insulation stands out for itshigh thermal capacity and density. These characteristics enable it to provide excellentthermal phase shift, i.e., the ability to delay heat transfer. In attics, where the roof accounts for up to35% of a home's heat loss, this property becomes a major asset for comfort in both summer and winter.
A dense and effective insulator
Contrary to popular belief, cellulose insulation by blowing exerts acontrolled load on ceilings. Tests carried out by CERIB (reports no. 012932 and no. 012933 of November 20, 2018) on BA13 ceilings fixed to metal frames show adeformation of less than 5 mmwith an insulation mass of16 kg/m².
These results fully comply with the requirements of DTU 25.41 "Plasterboard structures", which defines the strength and stability requirements for suspended ceilings.
How high can thermal resistance go?
Tests validated by ECIMA confirm thatblown cellulose insulationcan achieve athermal resistance of 12 m²·K/W, equivalent to a thickness of approximately600 mm. To comply with RE2020, professionals generally apply a thermal resistance of R = 10 m²·K/W, which is also the maximum thermal resistance used for renovation work (which varies between 7 and 10 m²·K/W). This level of insulation therefore offers an excellent compromise between energy performance and mechanical safety.
Technical recommendations
- Suspension cables: they must have a breaking load at leastthree times greaterthan the working load (according to DTU 25.41).
- Plasterboard: tests were carried out on twoNF BA13 references, fixed at a center-to-center distance of 0.60 m and spaced 1.20 m apart with hangers.
- Permissible load: approximately16 kg/m²without significant deformation.
These parameters ensure that cellulose insulation besafelyinstalled on a standard plasterboard ceiling.
Why choose cellulose insulation other types of insulation?
1. Sustainable thermal performance
Cotton wool retains its insulating properties over time, unlike some synthetic insulators that settle or lose their effectiveness after several years.
2. Enhanced summer comfort
Its high thermal massgives it much greater inertia than mineral wool, delaying heat peaks by several hours (more than 9 hours compared to 3 to 5 hours for mineral insulation).
3. Reduced environmental impact
Made from recycled materials, cellulose insulation France cellulose insulation is aneco-friendly, locally sourced insulation product that is ACERMI certified and complies withRE2020 requirements.
A proven solution validated by science
ECIMA and CERIB tests providesolid scientific proof: cellulose insulation, even when blown in thick layers,does not alter the strength of plasterboard ceilings thatcomply with DTU 25.41.
It also offers superior thermal and acoustic performance, while being environmentally friendly.
For homeowners and contractors, this solution isa reliable, high-performance, and long-lasting choice.
Before installation, it is essential tocheck that the ceiling and hangers are compliant and to consult a qualified professional.
