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Insulation

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Insulation Contents:

CSI NUMBERS
DEFINITION
CONSIDERATIONS
COMMERCIAL STATUS
IMPLEMENTATION ISSUES
GUIDELINES

RESOURCES

CSI NUMBER

 Division 7 - Thermal & Moisture Protection
07200 Insulation

DEFINITION:

There are several types of insulation addressed in this section that can be used in walls, floors, and ceilings.

Cellulose insulation is made from recycled newspaper and treated with fire retardants and insect protection. Borates, derived from the mineral Boron, are natural materials that can be used as fire retardants and insect repellents in cellulose insulation.

CFC and HCFC insulation refers to the blowing agents that contain chlorofluorocarbons used in making many rigid insulating sheathing products. Extruded polystyrene and polyisocyanurate foam insulation boards are currently made with CFC or HCFC blowing agents.

Agricultural fiber insulation is available in the form of cotton insulation made with mill waste, low grade, and recycled cotton. It is treated with a non-toxic fire retardant and comes in batts comparable to fiberglass insulation batts.

Cementitious foam insulation is made from magnesium from sea water and blown in place with air.

Perlite insulation is made from a natural occurring volcanic mineral and is often used as loose fill insulation in concrete block cavities.

CONSIDERATIONS:

Insulation materials play a primary role in achieving high energy efficiencies in buildings. There has been concern over the health impacts of the material constituents of insulation ever since the problems associated with asbestos became apparent, followed by the banning of urea formaldehyde based insulation. The health concerns have currently spread to fiberglass and cellulose insulation.

Fiberglass is considered a risk by some because of the insulation fibers ability to become airborne and be inhaled similar to asbestos.

Cellulose insulation uses recycled newsprint that contains printers inks which can possibly outgas formaldehyde into a home. If there is any outgassing from inks, it should fall well below levels irritating most persons. However, an environmentally-sensitive person should be careful in selecting cellulose and install a vapor retarder between the insulation and the living space. (Note that the vapor retarder can exacerbate mildew problems if humidity levels in the house are high.)

There are also chemical additives often added to treat cellulose that are not thoroughly understood from an indoor air quality standpoint. Cellulose insulation that is treated with borates is preferred. Cellulose insulation can be bound together as a wet spray and installed in open wall cavities where it effectively seals the entire wall.

Rigid board insulations employed as sheathing on homes have played an important role in achieving high R-values. The use of CFC's in many of these materials has caused increased release of chlorine molecules into the atmosphere contributing to ozone depletion. HCFC's outgas a lesser amount of chlorine molecules. However, the severity of the ozone depletion situation has led to the recommendation to avoid both types of insulation blowing agent. Alternatives in rigid board insulation are available that do not use CFC's. (See Engineered Sheet Products section.) Any rigid expanded polystyrene insulation does not have CFC's.

Cementitious foam insulation is available commercially in one product: Air-Krete. There are no installers of this type of insulation in our region. It is also more costly where available. This type of insulation is considered the most benign from an indoor air quality standpoint.

Perlite insulation is in a loose form suitable to fill the cavities in building block. Perlite can be bound into other materials and used in sheet form. It is commonly used in commercial roofing material and can be used as an aggregate in concrete. It is non-flammable, lightweight and chemically inert.

Not listed in the first Green Building Guide is the use of rockwool insulation. Rockwool is recycled steel slag (a landfill material). It is available as blow-on wall insulation (a starch binder is used) and as loose blow-in attic insulation. It offers very good energy performance, will not burn, and is chemically inert.

Commercial
Status		 Implementation
Issues
technology suppliers cost financing public regulatory
Cellulose
CFC / HCFC
Cellulose w/ Borates
Agri. Fiber
Cementitious
Perlite

Legend
green Satisfactory
yellow Satisfactory in most conditions
red Satisfactory in Limited Conditions
black Unsatisfactory or Difficult

COMMERCIAL STATUS

TECHNOLOGY:

Well-developed and changing. More recycled-content types are being developed. Cotton insulation is new.

SUPPLIERS:

Adequate for cellulose insulation; new suppliers for cotton insulation are currently being established. Air Krete requires trained installers. Perlite and rockwool are available.

COST:

Prices can vary according to installer.
Cellulose/cotton/fiberglass insulation: less than $.20 per square foot for R-19 uninstalled.
Wet blown cellulose insulation: 50% more installed.
Air Krete: $2.00 per square foot for 2x6 walls installed.
Perlite (as loose fill): $5.00 to $8.00 per 4 cubic feet.
Rockwool: $0.50 per square foot installed in 2 x 4 wall, comparable to cellulose in attic.

IMPLEMENTATION ISSUES

FINANCING:

Available.

PUBLIC ACCEPTANCE:

The general public is mostly unaware that CFC's can exist in insulation. Cellulose insulation is commonly accepted. Cotton insulation is attractive to environmentally-aware individuals and those doing their own insulating work as it will not cause skin irritation. Perlite insulation is relatively unknown to the general public. Cotton and perlite are not likely to be negatively perceived. Rockwool is relatively unknown as a modern insulation option.

REGULATORY:

Must meet flame spread and smoke density requirements, listed in Section R-217 of the CABO One and Two Family Dwelling Code.

GUIDELINES

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This document was adapted to HTML by Bill Christensen, sysop and environmental editor of Texas InfiNet, an online community for progressive information.

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