Insulation is a First Line of Green Defense

Rigid Foam Insulation

Batt Insulation

Spray Foam Insulation

Mineral Wool Insulation

Radient Barriers

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Insulation

Adding insulation to your home is a very green step because it immediately improves energy efficiency.

Most people realize they need insulation in the walls and attic, but will overlook their crawlspaces and pipes. In fact, the simple task of repairing broken windows or sealing spaces where air can get into the house significantly contributes to the home’s ability to resist heat flow up in the winter and in during the summer.

There are many other reasons to insulate the home besides preventing heated air flow. Insulation can make your home more comfortable, reduce your energy bills, and reduce indoor air pollution. It is a good idea to walk around the home to look for areas where insulation is inadequate or where outside air can get in. Start at the top of the house in the attic and work your way down to the crawlspace. You may be very surprised at what you find. For example, can you see daylight where a pipe exits the house to the outside? If so, the area around the pipe needs to be filled with some type of insulation.

There are a number of green insulation options available to accommodate the many different area configurations found in a home. A good example is the all natural wool insulation batts or rolls. Since it is all natural, it is also biodegradable. There are even radiant barriers that can be attached to the rafters or underside of the roof sheathing to block the heat entering from a sun-heated roof.

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Rigid Foam

Insulation

What is it?

Rigid foam (or foam board) insulation is made from polystyrene, polyisocyanurate, or polyurethane. These chemicals are derived from fossil fuels and expanded or extruded into rigid material using a blowing agent. Rigid foam has a superb insulating quality, with R-values ranging from R3.6 to R8 per inch depending on the density (nearly twice the R-values of fiberglass and cellulose). It can come with foil facing, which acts as a radiant barrier.

Why do it?

Environmental Qualities

Rigid foam made from polystyrene can be melted and re- expanded into new insulation or packaging.

Pros:

Extremely efficient: some of the highest R-values per inch

Can be applied to both interior and exterior walls

Acts as a continuous insulation layer without thermal bridging

Acts as an air and vapor barrier

Cons:

Extruded polystyrene (XPS) is made using an ozone-depleting blowing agent and contains HBCD (a toxic flame retardant)

In the first two years after manufacture, the R-value of polyisocyanurate and polyurethane insulation can decrease due to thermal drift

Maintenance:

If installed correctly and protected from moisture, rigid foam insulation doesn’t require any maintenance.

Timeline:

Depends on the area requiring installation, but set aside at least one day for an entire room.

Steps:

1.Find out what type of insulation you currently have and compare it to the standard R-value for your region at http:// www.energystar.gov/?c=home_sealing.hm_improvement_ insulation_table.

2.Measure the depth of your current insulation and add the correct number of inches to meet your region’s standard thickness (and R-value).

3.Calculate the square footage of the area you need to insulate and purchase the number of 4x8 sheets that will fill this space (better buy more than not enough).

4.Gather or buy the necessary tools: tape measure, straight edge, utility knife, level, and lightweight stapler. Also consider getting a portable light.

5.Make sure your house is ventilated so heat and condensation don’t accumulate. Plug all leaks. If you haven’t already, paint the walls with waterproof paint to prevent the transfer of moisture.

6.After taking measurements of the area that needs insulation, scribe the surface of the uncut foam board using the point of a nail, and follow this line about halfway with a utility knife. Then, to complete the cut, break the board over the edge of a table or work surface.

7.If installing rigid foam in an unfinished wall, turn the newly cut board so that the facing is on the outside, towards you, and press the board into the wall cavity so that the studs keep it in place. Seal the perimeter of the board with caulk or expanding foam.

8.If installing rigid foam on a masonry wall (such as the concrete wall of a basement), draw a line of foam construction adhesive around the perimeter of the back of the newly cut board (nonfaced side) and an X across the center. Then press the foam board against the wall. Seal the joints between foam boards with expanding foam or weather-sealing tape.

9.If using polystyrene or polyurethane, staple a 6 mil plastic sheet to the foam board to act as an air barrier.

10.If using polyurethane, add a ½-inch sheet of gypsum or drywall to the plastic-covered foam board using a foam construction adhesive. This will protect the highly flammable polyurethane from catching fire.

Cost Estimator:

1-inch-thick expanded polystyrene (EPS) costs about $0.32 per sq. ft. The same thickness in extruded polystyrene (XPS) costs about $0.47 per sq. ft., and in polyisocyanurate (polyiso) about $0.60 per sq. ft. A professional installation will add around $0.55 to the price per sq. ft.

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Quick Tips:

Installing rigid foam insulation on interior walls can be a DIY job. However, because of the importance of air and water sealing, you should call a professional to do any exterior installation.

Polyiso has a foil facing on both sides. It doesn’t need an interior plastic vapor barrier or a layer of drywall for fire safety.

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Batt

Insulation

What is it?

Blanket insulation is precut into batts and rolls and is made from fiberglass, mineral wool, plastic fiber, or natural fiber (i.e. cotton, sheep’s wool, or straw). Batts have an R-value of R2.2 to R4 per inch, depending on material. (R-value is a measure of insulation’s ability to resist heat traveling through it. The higher the R-value, the better the thermal performance of the insulation.) Batts are sold in varying thicknesses, with total R-values from R11 to R38 (the industry standard). Some batts come wrapped in a foil facing, which acts as a radiant barrier, or in a plastic facing, which acts as a moisture barrier. Used to insulate floors, ceilings, and unfinished walls, batt insulation is the most popular type of insulation in North America.

Why do it?

Environmental Qualities

Added home insulation can drastically reduce a home’s energy consumption

Batt insulation can be made from recycled materials and industrial waste products

Cotton batt insulation will not contaminate indoor air

Pros:

Great for small projects: readily available, inexpensive, little equipment required

Cons:

Batt materials, particularly fiberglass, can irritate the skin

Fiberglass batts have to be fitted perfectly for the insulation to be effective: even professional installers will sometimes skimp on quality because it’s not a high-price job and they don’t want to take the time to do it right

Some batt materials contain known carcinogens such as

formaldehyde

Walls need to be completely exposed to install batt insulation

Maintenance:

When correctly installed, batt insulation needs little to no maintenance and in some cases, such as wall insulation, it’s inaccessible anyway. Attic and crawlspace insulation should be inspected at least twice a year for rodent damage, and any damaged sections should be replaced. Also, with crawlspace insulation, check to make sure all the insulation hangers are in place and none of the batts are sagging.

Timeline:

One full day each for the attic and crawlspaces. Half a day per wall.

Steps:

The steps to install mineral wool will depend on the type of

Steps:

Quick Tips:

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1.Find out what type of insulation you currently have and compare it to the standard R-value for your region at http:// www.energystar.gov/?c=home_sealing.hm_improvement_ insulation_table.

2.Measure the depth of your current insulation and add the correct number of inches to meet your region’s standard thickness (and R-value).

3.Calculate the square footage of the area you need to insulate and purchase the number of batts that will fill this space (better buy more than not enough).

4.Gather or buy the necessary tools: tape measure, straight edge, utility knife, and lightweight stapler or hammer tacker. Also consider getting a portable light, a rake to adjust the insulation, and insulation supports/hangers.

5.Make sure your house is ventilated so heat and condensation don’t accumulate. Plug all leaks.

6.Wear long sleeves and pants, work gloves, safety glasses, and a dust mask or respirator to avoid irritating your skin or breathing in harmful substances.

7.Push batts all the way into each cavity between studs or joists. If you’re installing the insulation in a crawlspace under a floor, use insulation hangers to hold the batts in place.

8.Split the batt around any cable, piping, or wire so that the insulation completely encompasses it.

9.Cut the batt half an inch longer than the cavity so that it’s snug.

10.Stuff skinny strips of insulation around the windows and doors, filling all cavities.

Cost Estimator:

The cost of batt insulation varies based on square footage, R-value, facing, and whether you have it installed professionally. Fiberglass batts generally run from $0.75 to $2.00 per sq. ft., and cotton batts cost about twice as much. Mineral wool batts cost an average of $1.08 per sq. ft.

Do NOT tightly pack insulation. If using fiberglass, this will reduce the R-value. Insulation should always be loosely packed so that it will retain the air pockets necessary to absorb sound and heat.

Mineral wool is easier to cut and install than fiberglass, and it repels moisture. It’s also very resistant to heat, so you can use it around chimneys or flues.

Fiberglass batts don’t block air well, so they should be installed with an air barrier (e.g. a facing).

Vacuum your clothing immediately after completing the insulation, so that the tiny pieces of fiberglass or other materials won’t irritate your skin.

If you’re concerned about carcinogens, Knauf makes a line of insulation called EcoBatt, which contains at least 61.9% recycled content, is made mostly of sand, and has no phenol, formaldehyde, acrylics or artificial colors. Also, Ownens Corning sells EcoTouch batts, which are formaldehyde-free.

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Spray Foam

Insulation

What is it?

Insulation doesn’t always come in batts or boards. It can also come in liquid form and be sprayed, foamed- in-place, injected, or poured into cavities. Because spray foam insulation requires special equipment and certifications, installing it isn’t a DIY job. However, this type of insulation has many benefits that are worth the added cost. For instance, closed-cell spray polyurethane foam (SPF) has twice the R-value of batt insulation and serves as an excellent air barrier. SPF can have a density of 0.5 lb (open-cell) or 2 lb (closed cell). Open-cell is less expensive than closed-cell and uses fewer materials, but it’s more permeable to moisture, requiring a vapor barrier. In addition to polyurethane, foam can be made from cementitious, phenolic, or polyisocyanurate (polyiso) material.

Why do it?

Environmental Qualities

Cementitious foam is nontoxic, resilient, and 100% fireproof; it also blocks air, heat, and sound, and can be disposed of safely

Pros:

Superb air barrier: Liquid state of foam allows it to fill even tiny cavities

Simple, quick installation (though requires special equipment)

Cons:

Requires professional installation

In the first two years after manufacture, the R-value of polyisocyanurate and polyurethane insulation can decrease due to thermal drift

More expensive than batt insulation

Difficult to remove for replacement or home renovation

Maintenance:

Less than fiberglass (batt) insulation.

Timeline:

Installation takes 1-2 days.

Steps:

1.Have a building engineer inspect your home and/or get several contractor estimates. You should be able to get a good idea from them how to make your home more energy efficient.

2.Once you’ve determined that spray foam is the best insulation to meet your home’s needs, decide on a suitable type of foam.

3.Select a good foam manufacturer and a reputable contractor to install the insulation.

4.Monitor the installation process, but stand clear of the foam while it’s being sprayed in. Do NOT enter the application site.

5.While the foam is setting and curing, you may want to stay at a friend’s house or at a hotel so that the fumes and odor can dissipate.

Cost Estimator:

Open-cell SPF costs $0.44 to $0.65 per board foot ($1.00 to $1.20 per sq. ft.). Closed-cell SPF costs $0.70 to $1.00 per board foot ($1.75 to $3.00 per sq. ft.). These figures apply to an insulation value of R13 for a 2-by-4-framed wall. Open-cell SPF usually needs a vapor retarder (e.g. a layer of gypsum board or drywall finished with vapor-retarder paint), which will increase the price. The cost of Air Kretevaries by manufacturer, so you’ll have to get quotes from more than one company.

Quick Tips:

Spray foam is messy. There’s no telling where those drops of liquid foam will end up! They can ruin clothes and delicate equipment. During installation, remove all house occupants and nonessential crew from the application site. Keep drop cloths, caulk, and tape on hand to catch any drips.

If using SPF, wait at least three days before entering the house after installation. This will reduce the risk of health problems from outgassing.

The source of lingering odors after spray foam installation has yet to be conclusively linked to the spray foam itself. It’s likely that you won’t experience this problem, but take the possibility into consideration before ordering spray foam.

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Mineral

Wool

Insulation

What is it?

Mineral wool is an example of an insulation material that can be manufactured into products that are installed into a variety of ways. It is made from both an industrial waste product from steel production (slag- wool) and rock such as basalt (rock-wool).

Mineral wool can be installed as a loose-fill material (blown-in insulation), batt insulation, semi-rigid boards, and rigid board, making it one of the most versatile insulation materials available. It has the added benefit of having natural fire and sound resistance properties due to its density. In its rigid board form, mineral wool also has excellent drainage properties, making it a good foundation insulation material.

Why do it?

Environmental Qualities

Made from industrial waste (slag-wool)

Pros:

Versatility: can be installed as loose-fill, batt, or board insulation

Natural fire resistance properties (greater than fiberglass)

Natural sound resistance properties

Natural water drainage properties

Cons:

More expensive than fiberglass and cellulose

Mineral wool made from rock (rock-wool) has a much higher environmental impact

Mineral wool fibers can be an irritant and should be separated from interior spaces

May contain possible carcinogenic chemicals

Maintenance:

Mineral wool is a very dense and durable material that needs minimal maintenance since it is naturally mildew and vermin resistant.

Timeline:

Depending on the type of mineral wool product you are installing (loose-fill, batt, semi-rigid board, or rigid board), anywhere from a couple of hours to a couple of days.

Steps:

The steps to install mineral wool will depend on the type of mineral wool product you are installing (loose-fill, batt, semi- rigid board, or rigid board). These different types of insulation are described in other chapters of this book.

Cost Estimator:

Programmable thermostats generally cost between $25 and $100.

Cost Estimator:

The cost will depend on the type of mineral wool product you are installing (loose-fill, batt, semi-rigid board, or rigid board). Mineral wool batt insulation (R-16.8) costs about $1.15 per square foot.

Quick Tips:

If you do install yourself, always wear a dust mask, safety glasses and gloves when installing any insulation.

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Radient

Barrier

What is it?

Installing a radiant barrier is great way to protect your home from heat gain. Unlike insulation, which slows the transfer of heat through conduction, a radiant barrier reflects infrared radiation. This is particularly important during hot summer months when the sun’s intense radiation heats up the attic, accounting for 15 to 25% of your home’s heat gain. According to a study on homes in Florida, a thin sheet of reflective material (such as aluminum) can reduce heat gain by 8-12% each year. What’s more, it’s easy to install, even for homeowners with little building knowledge.

Why do it?

Environmental Qualities

Energy efficient: Your home will gain less heat in the summer and therefore you will use less energy cooling it.

Pros:

Reduced cooling costs

Increased comfort during the summer

Cons:

Moisture can build up within attic insulation if installed incorrectly

Maintenance:

If the radiant barrier is installed directly on the attic floor it needs to be cleaned annually to remove dust buildup. Also, if you don’t use a moisture-permeable radiant barrier, you need to perforate the barrier at regular intervals to allow moisture to be released.

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Timeline:

4-8 hours.

Steps:

1.Calculate the area that needs to be insulated and purchase a roll of radiant barrier in the appropriate square footage.

2.Gather or buy the necessary tools: head-lamp, staple gun, and utility knife. Make sure you wear a dust mask, long sleeves, and gloves when working in the attic.

3.For direct installation, simply roll the barrier over the insulation making sure the reflective side of the barrier faces up to reflect heat away from the home. Cut the barrier to fit around rafters and staple the barrier to the attic trusses. Make sure to leave soffit vents uncovered. This insulation method is the easiest and cheapest, but there are some downsides. The barrier will make it harder to access ducts, wires, recessed lighting, etc.You also have to worry about dust and moisture. According to the Department of Energy, dust will decrease the amount of heat the barrier reflects by as much as half, while moisture can condense within the insulation.

4.If you’re attaching the radiant barrier to the roof rafters, it’s best to work with an assistant. One person can unroll the barrier while the other staples it to the rafters. Again, make sure the reflective side is facing the roof, away from the home. You may need to place plywood over the floor joists and use a step ladder to get the top of the roof. Barriers along the rafters will collect minimal dust, and moisture is not an issue. However, because there is more surface area along the roof line, you will need more material, which will add to cost.

Cost Estimator:

A 100-sq.ft. roll of radiant barrier will cost between $40.00 and $45.00. Moisture permeable barriers will cost more. For an average 1500-sq.ft home, the total cost of installing a radiant barrier yourself will range from $400 to $700, depending on the size and structure of your attic and roof.

Quick Tips:

If you’re installing a radiant barrier directly over your attic insulation, make sure it is a vapor- permeable barrier. This will prevent moisture (leaking from the home into the attic) from condensing under the barrier and in the insulation.

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