Aerogel is the most expensive option, but it is the best type of insulation available.
Fiberglass
is a cheaper option, but it requires careful handling. Mineral wool is effective, but not fire resistant.Cellulose
is fire resistant, environmentally friendly, and effective, but difficult to apply.Manufacturers now produce medium and high density fiberglass insulation products that have slightly higher R-values than standard blocks. These denser products are intended to isolate areas with limited cavity space, such as the roofs of cathedrals. Fiberglass insulation is made of molten glass that is spun or blown into fibers. Most manufacturers use between 40% and 60% recycled glass content. Loose-fill insulation should be applied with an insulating blowing machine in open blowing applications (such as attic spaces) or closed cavity applications (such as those found inside existing walls or covered attic floors).
Learn more about where to insulate. The new HP BIBS is an economical hybrid system that combines BIBS with polyurethane spray foam. Mineral wool contains an average of 75% post-industrial recycled content. It does not require additional chemicals to be fire resistant and is usually available as a blanket (blocks and rolls) and as a loose fill insulator.
Cellulose insulation
is made from recycled paper products, mainly newsprint, and has a very high content of recycled material, generally 82% to 85%.First, the paper is reduced to small pieces and then fibrized, creating a product that is hermetically packed into building cavities. Manufacturers add the mineral borate, sometimes mixed with the less expensive ammonium sulfate, to ensure resistance to fire and insects. Cellulose insulation, when installed with appropriate densities, cannot settle in the cavity of a building. Cellulose insulation is used in both new and existing homes, as loose filling in open attic installations and dense building cavities, such as cathedral walls and roofs. In existing structures, installers remove an outer cladding strip, usually up to the waist; drill a row of three-inch holes, one in each stud, through the wall cladding; insert a special filling tube into the top of the wall cavity; and blow the insulation into the building cavity, usually to a density of 1.5 to 3.5 pounds.
When the installation is complete, the holes are sealed with a plug and the coating is replaced and retouched if necessary to match the wall. In new buildings, cellulose can be sprayed with moisture or it can be installed dry behind a net. When sprayed with moisture, a small amount of moisture is added to the tip of the nozzle, which activates the product's natural starches and causes it to adhere to the inside of the cavity. Moisture-sprayed cellulose is usually ready for wall cladding 24 hours after installation. Cellulose can also be blow dried to form meshes stapled onto building cavities. Some natural fibers such as cotton, sheep's wool, straw, and hemp are used as insulation materials.
Polystyrene, a clear colorless thermoplastic, is commonly used to make foam panels or insulation panels, concrete blocks, and a type of loose fill insulation consisting of small polystyrene beads. Molded expanded polystyrene (MEPS), which is commonly used to insulate foam plates, is also available as small foam beads. These beads can be used as insulation for pouring concrete blocks or other hollow-wall cavities but they are extremely light statically charged very easily and are notoriously difficult to control. Other polystyrene insulation materials similar to MEPS are expanded polystyrene (EPS) and extruded polystyrene (XPS). Both EPS and XPS are made of polystyrene but EPS consists of small plastic beads that fuse together while XPS starts out as a molten material that is extracted in a shape and forms sheets.
XPS is most commonly used as insulation for foam plates while EPS is commonly produced in blocks which can be easily cut to form plate insulation. Both EPS and XPS are often used as insulation for structural insulating panels (SIP) and insulating concrete forms (ICF). Over time the R-value of XPS insulation may decrease as some of the low-conductivity gas escapes and air replaces it a phenomenon known as thermal drift or aging. The thermal resistance or R-value of the polystyrene foam plate depends on its density while loose-filled or pearl-filled polystyrene insulation generally has a lower R-value compared to foam plate. Polyisocyanurate or polyiso is a type of closed-cell thermosetting plastic foam that contains a gas free of hydrochlorofluorocarbons with low conductivity in its cells. Polyisocyanurate insulation is available as liquid sprayed foam and rigid foam plates.
It can also be converted into laminated insulation panels with a variety of coatings. Polyisocyanurate insulation applications with in-situ foam are usually cheaper than installing foam plates and can work better because liquid foam molds to all surfaces. Over time the R-value of polyisocyanurate insulation may decrease as some of the low-conductivity gas escapes and air replaces it a phenomenon known as thermal drift or aging. Experimental data indicate that most of the thermal drift occurs within the first two years after manufacture of the insulating material. Aluminum and plastic coatings on rigid polyisocyanurate foam panels can help slow down this aging process while reflective sheeting if properly installed and oriented towards an outdoor space can also act as a radiant barrier depending on size and orientation of air gap this can add another R-2 to overall thermal resistance. Some manufacturers use polyisocyanurate as insulation material in structural insulation panels (SIP).
A foam plate or liquid foam can be used to manufacture SIP while liquid foam can be injected between two wooden coatings under considerable pressure when it hardens it produces strong bond between foam and coatings. Wall panels made of polyisocyanurate are usually 3.5 inches (89 mm) thick while roof panels are up to 7.5 inches (190 mm) thick these panels although more expensive are more resistant to fire and diffusion of water vapor than EPS they also insulate 30% - 40% better for given thickness.
