Insulation plays a key role in the energy efficiency, comfort and sustainability of our homes. In recent years, there has been a growing focus on cellulose-based insulation materials as an environmentally friendly alternative to traditional insulation. But is it still a good choice? In this article we look at the pros and cons of cellulose insulation to help you make your decision.
What is cellulose insulation?
The main raw material for cellulose insulation is recycled paper, which is treated with special flame retardants, usually borate* or boric acid*. Its consistency can be in the form of loose fill, which is applied by blow moulding, or it can be available in the form of hard pressed slabs.
Benefits
- An environmentally friendly solution
One of the key benefits of cellulose insulation is that its main raw material is recycled paper, which significantly reduces waste. Its production requires less energy than conventional insulation materials. - Excellent thermal insulation
Cellulose has low thermal conductivity, effectively retaining heat in the winter and preventing the home from heating up in the summer heat. - Sound insulation
The cellulose structure is excellent at absorbing noise, making it particularly beneficial for houses built along busy roads. - Air barrier and vapour barrier
The material fills all small gaps and cracks, preventing thermal bridges. It also helps regulate humidity, which improves the indoor climate. - Fire-retardant property
Cellulose treated with borate or boric acid is resistant to fire, which increases safety.
Disadvantages
- Sensitivity to moisture
If cellulose insulation is exposed to prolonged moisture, it may lose its effectiveness and mould or fungal growth may develop. - Requires expertise
Spray application requires special tools and expertise, which can make installation more expensive. - Risk of corrosion
Without improper installation or proper vapour barrier, the material may corrode over time. - Periodic re-spraying is required
The material may shrink slightly over time, which may require re-filling. - Hazards to rodents
Cellulose can attract rodents if not handled properly.
When is cellulose insulation a good choice?
Cellulose insulation can be particularly suitable for those looking for an environmentally friendly and energy efficient solution. It is important to consider moisture protection and proper construction to ensure the material remains effective over the long term. If you’re looking for a sustainable and efficient solution, cellulose can be a great choice, but attention to detail is important when it comes to the construction.
Cellulose insulation tutorial video:
* Borate is commonly referred to as sodium tetraborate, also known as borax. It is often used in cellulose insulation for flame retardant and pest control. In addition to borax, boric acid, which has similar properties, is also commonly used. Both are natural minerals that effectively reduce fire risk and biological damage while having minimal environmental impact.
These are the questions you may have asked yourself about blown cellulose insulation:
– Is it necessary to use vapour barrier and waterproofing films for this insulation solution?
Yes, when applying cellulose insulation, it is equally necessary to use a vapour barrier film on the inside to prevent moisture from entering the insulation material and a waterproofing film on the outside to provide protection against external moisture while allowing the structure to ventilate. This is particularly important for lightweight construction methods.
– This thermal insulation method can be particularly advantageous for insulation of multiple pipes or wiring to be placed between?
One of the biggest advantages of cellulose insulation is the blow-in technology, which allows the insulating material to easily fill small gaps in the wall structure, making insulation around pipes and wiring fast and efficient. In contrast, this process is considerably more difficult and time-consuming with board insulation materials. So yes, cellulose is an excellent solution in these situations.
– If the point is the thermal insulation properties of cellulose, then on that basis, in agricultural areas where there is a surplus of straw, can we achieve the same potential use by treating it with borax and shredding it?
In theory, an insulating material made from wheat straw could function in a similar way to cellulose insulation, provided it is properly treated with flame retardants and bio-damage inhibitors. The thermal insulation properties of straw are basically favourable and, where available as agricultural surplus, it can be a cost-effective and sustainable alternative. However, the chopping and handling of straw should ensure a homogeneous texture and adequate fire protection. This may make its use as inflatable insulation feasible.
– There is also some historical tradition, and you can see attempts at straw bale construction. Folklore has it that it was woven with wire mesh and plastered with adobe to protect against rodents and fire, but following modern logic, would a borax-treated straw bale be as easily incorporated into the masonry of a lightweight house as mineral wool board insulation?
Straw bale construction is a historically proven technology and can be improved with today’s techniques. When bales are treated with borax or other flame retardants, their fire safety is significantly improved. When installed in the masonry of modern lightweight houses, they can even offer an alternative to mineral wool board insulation.
– How is cellulose inflatable insulation installed?
The cellulose is injected into walls, slabs or other cavities using a blowing machine, where the loose insulation material fills the entire surface of the gaps and cavities.
– How effective is the thermal insulation of cellulose insulation?
The thermal conductivity (λ-value) of cellulose is generally between 0.038 and 0.040 W/mK, which is competitive with other insulation materials.
– How noise insulating is cellulose insulation?
The fibrous structure of cellulose is excellent at absorbing sound waves, making it an effective solution for noise insulation, for example in houses built in busy areas.
– How fire resistant is cellulose insulation?
Cellulose insulation treated with boron compounds is self-extinguishing, meaning it will not spread in the event of fire. It complies with the building industry’s fire safety regulations, but the combustibility of adjacent materials must be taken into account during installation.
– How environmentally friendly is cellulose insulation?
Cellulose insulation is extremely environmentally friendly because it is made from recycled paper. It is produced with low energy consumption and is biodegradable. It is therefore an ideal choice for those looking for sustainable building solutions.
– How much does cellulose insulation cost compared to traditional insulation materials?
Cellulose insulation is generally competitively priced, often cheaper than, for example, mineral wool or polyurethane foam. The cost depends on the size of the project and the complexity of the installation, but the thermal and sound insulation properties make it cost-effective in the long run.
– How long does it take to install cellulose insulation?
The installation time depends on the size of the building and the technology used, but experienced professionals can complete the work on a small building in as little as a day.
– What maintenance does cellulose blown-in insulation require?
Cellulose insulation requires minimal maintenance. The key is to ensure adequate ventilation and protection from moisture, as persistent dampness can reduce the effectiveness of the material.
– How resistant is cellulose insulation to moisture?
Cellulose has a natural moisture management ability because it can absorb and evaporate a certain amount of moisture. However, its effectiveness can deteriorate in persistently humid environments, so good ventilation and moisture protection are essential.
– Can cellulose blown-in insulation be used to renovate old buildings?
Yes, it is particularly suitable for old buildings, as the inflatable technology allows gaps and cavities to be filled without significantly disrupting the existing structures.
– How does cellulose insulation improve the energy efficiency of a building?
Cellulose insulation reduces heat loss, resulting in lower energy consumption. As it fills the walls and roof structure without gaps, it significantly reduces thermal bridges, thus increasing the energy efficiency of the building.
– How durable is cellulose blown-in insulation?
When properly installed, cellulose insulation is extremely durable, lasting up to several decades. However, it is important that the building is properly ventilated and moisture controlled.
– How does cellulose insulation relate to health concerns?
Cellulose insulation is non-irritating to the skin and respiratory tract, unlike some traditional insulation materials. The boron compounds it is treated with inhibit the growth of mould and pests, further enhancing a healthy indoor environment.
– How thick should the cellulose insulation layer be for optimum performance?
The optimal thickness depends on the type of building, insulation requirements and climatic conditions. In general, a layer thickness between 10-20 cm is recommended, but in colder climates or for passive houses, thicker insulation may be necessary.
– For which building types can cellulose insulation be used?
Cellulose insulation has a wide range of applications, including residential, office, industrial and public buildings. It is particularly beneficial in the renovation of existing buildings where it is important to fill gaps and voids.
– What certifications does cellulose insulation have?
Cellulose insulation materials generally have certificates in accordance with international and national building standards, guaranteeing compliance with fire, thermal insulation and environmental protection requirements. Specific certificates should be obtained from the manufacturer.
– How does cellulose blown-in insulation compare with Styrofoam (EPS) insulation?
The advantages of cellulose insulation include sustainability, natural material and excellent sound insulation properties. EPS (styrofoam) has better moisture resistance and a lower thermal conductivity, but is less environmentally friendly and its use is mainly limited to flat surfaces. The ideal choice depends on the needs of the project.