Types of Insulation

There are several types of insulation available on the market today, each with advantages and disadvantages.

• Batts and Blankets –Batts are cut to specific lengths to comply with standard spacing of wall studs and attic or floor joists. Blankets are rolls of uncut insulation that are cut to your specific needs. Batts and blankets come in the following fibers:
o Fiberglass – A wool-like material used as insulation in weatherproofing. Originally used as a substitute for asbestos, however there is also a concern about fiberglass having the ability to become airborne and be inhaled. Other concerns are the odor released by the binder materials and the potential to cause skin allergies. Fiberglass comes in a medium and high-density batt insulation having a somewhat higher R-value than fiberglass products of the past. Used for areas like cathedral ceilings with small cavity spaces.
o Mineral Wool - Acts as a drainage layer, keeping surface and ground water away from the home’s foundation. Mineral wool is also known as rock wool, consisting of natural minerals such as basalt, or slag wool. Rock and slag wool products supply fire protection, as well as sound control and reduction. Airborne levels of rock and slag wool fibers are very low. However, if sufficient amounts of rock and slag wool are released into the air during handling, some people may experience temporary upper respiratory irritation. The irritation will subside once you are away from the product.
o Plastic Fiber – Insulation made primarily from recycled plastic milk bottles. It is flame retardant but does melt when exposed to flame. It is not irritating to the skin like fiberglass.
• Concrete Block - Insulated concrete blocks can accommodate many walls in a home. Their cores are filled with insulation raising the average wall R-value. Concrete block insulation is normally used in new home construction or in homes undergoing major renovation. Since the installation of this type insulation involves masonry skills, it is recommended that you have a certified cement mason perform the install. The following products are normally used in concrete block insulation:
o Polystyrene - A colorless, transparent thermoplastic insulation often used by pouring into concrete blocks. It is very lightweight which can cause a problem with static and the beads tend to fall out of any holes or go everywhere in wind.
o Polyisocyanurate – Also known as Polyiso, a thermosetting type of plastic foam that contains a low-conductivity gas in its cells. After a period of time, the R-value can drop as some of the gas escapes and is replaced by air. Applying foil and plastic facings on the foam panels can help to stabilize the R-value.
o Polyurethane – A closed-cell foam insulation also containing a low-conductivity gas in its cells. Low-density foams are sprayed into open wall cavities and expand rapidly to fill the cavity sealing it off and providing good air sealing and flame resistance.
• Foam Boards – Rigid panels of insulation used to insulate most any part of your home. Provide good thermal resistance and can add structural strength to your home. Foam boards also use Polystyrene, Polyisocyanurate, and Polyurethane materials. Reduces heat transfer, air leaks, and has excellent resistance to moisture. It is best used in unfinished walls, floors, and ceilings.
• Loose Fill – A blown-in type of insulation using loose fibers blown into cavities or attics using special equipment. The biggest difference in loose fill and other insulations is their foam. They are broken down into granules, shreds, or nodules. These small particles form an insulation that can conform to any space without harming the structure. It provides resistance to air penetration and is well suited for use in areas where it is difficult to install other types of insulation. All loose-fill insulations are required to feature their installed and settled thickness on the bag label to alert you to the expected settled R-value. Loose fill uses cellulose, fiberglass, and mineral wool materials. Fiberglass and mineral wool were discussed above.
o Cellulose – Made from recycled wood fibers such as newspaper. The wood is shredded into small fibers that can be packed tightly into cavities. Chemicals are added to make it fire resistant and insect repellent. It inhibits airflow providing a thermal resistance but has the disadvantage of absorbing moisture and tends to settle more than other types of loose fill insulation. Therefore, you will want to install an extra 20% to counteract this settling.
• Insulating Concrete Form – Forms for poured concrete walls that have the insulation built into the walls as part of the structure. These forms provide a backing for drywall on the inside or for the brick on the outside of your home. Creates a high thermal resistance in your walls and is used in new construction. This type of insulation uses foam boards or foam blocks.
o Foam Boards - Rigid panels of insulation used in almost any part of your home. Foam boards provide good thermal resistance and can add structural strength. The most common types of materials used in foam boards are polystyrene, polyisocyanurate, and polyurethane, which are discussed above.
• Reflective – Made from aluminum foils with backings such as, plastic film, kraft paper, polyethylene bubbles, and cardboard. Typically used between roof rafters, floor joists, or wall studs. Most effective in reducing downward heat flow depending on the spacing. Some reflective insulation materials conduct electricity so it should not come into contact with any electrical wiring.