Loose-fill Insulations are made up of loose fibers or fiber pellets which are normally blown into wall cavities or attics of the building with the help of exceptional pneumatic equipment. This type of insulation is more expensive than batt type insulation. However, it provides various benefits over other insulation types which are mentioned below:
- It can easily fill every crack and corner in the building.
- It provides excellent reduction in air leakage.
- It offers improved sound insulation as compared to batt insulation.
Loose fill insulations are generally installed via professionally competent installers. Their thermal resistance i.e. R-value generally varies between R-3 to R-4 per inch. “The most obvious difference between loose fills and other types of insulation is their form. They are either produced as—or broken down into—shreds, granules, or nodules. These small particles form fluffy materials that conform to the spaces in which they are installed.”1
Loose fill insulations are usually packed in bags for selling in the market.
Loose-Fill Insulation Materials
Three major types of loose-fill insulation materials include:
1. Fiber glass
2. Mineral wool
All these materials are regarded as “environmentally positive” since they get prepared from the recycling of waste materials.
It is basically a soft material similar to wool which can be employed as thermal insulation as well as textile material. It is generally available in pink and yellow color. Initially, it was considered to be a harmless insulation alternative to asbestos. “Fiber glass was used as a liner inside air supply ducts and air handler compartments of the ventilation system of homes and buildings built from the early 1960s through the late 1980s. It was used in ventilation systems as an insulator to prevent loss of hot or cold air and to reduce the noise from the blower fan.”2
But later, it was discovered that use of fiber glass carried few drawbacks too. Major problems associated with the use of fiber glass materials consist of:
- It can cause various health related issues such as skin allergies.
- It is also very dangerous for people who are extremely sensitive to any type of chemical reactions since fiber glass insulations are mainly formed by means of a phenol formaldehyde binder which tends to keep the fibers connected.
A major raw material used for the construction of fiber glass is boron which is found to be very flexible and fire resistant.
Mineral wool comes in two variants namely, slag wool and rock wool. Slag wool is mainly prepared from the waste residues i.e. slag left in an industrial iron ore blast furnace whereas rock wool is created from innate rocks. “Slag wool accounts for roughly 80 percent of the mineral wool industry, compared with 20 percent for rock wool. Given the relative use of these two materials, mineral wool has, on average, 75 percent post-industrial recycled content.”3
Mineral wool loose-fill insulation is almost identical to fiberglass insulation. The only difference between the two insulation types lies in their spinning process since the fiber glass insulating materials are spun from molten glass whereas mineral wools are spun either from blast furnace slag or natural rocks. However, both the insulations offer complete thermal protection via a “Blow-in Blanket” System i.e. BIBS in which insulations are blown-in into open stud cavities.
It is considered to be the most preferred type of loose-fill insulation material amongst all. “Cellulose loose-fill insulation is made from wastepaper, such as used newsprint and boxes that is shredded and pulverized into small, fibrous particles.”4
It is treated with chemicals to provide protection against fire, moisture and insects. It offers higher thermal insulation value and needs less energy for production as compared to other loose-fill insulations. Also, it forms an ultimate example for waste materials recycled for insulation.
Major application areas of loose-fill insulations include:
- They are particularly suitable for areas where other insulation types can not be conveniently applied, for example, areas involving uneven shapes and hitches.
- They are also considered apt for areas which are difficult to reach and insulate.
- They can be used in variety of places including enclosed cavities such as walls and open parts such as attics in a building.
- Usage of Blown-in loose fills is found helpful for retrofit applications since they are the only kind of insulation materials which can be employed without causing much damage to the existing building finishes.
- They are frequently employed for providing insulating layer over walls and ceilings available in mobile homes.
- Loose fill insulations can be occasionally applied in newly constructed buildings too.
- Loose fill insulation can be mixed with an adhesive so that it could be applied in the spray form into the wall cavities. By doing so, the possibility of gaps creation in the building’s thermal envelope gets reduced.