Insulation is a critically important building material for your home. It's one of the most efficient and cost-effective ways to save energy while making homes more comfortable and quieter. Made from recycled and renewable resources, fiberglass insulation is also a sustainable building product--one that has a positive impact on our environment, helping reduce energy consumption and the effects of global warming. Fiber glass insulation is still the most affordable when it comes to energy efficiency, but if you want maximum R-value performance; Spray Foam Polyurethane Insulation is now available.
Lower Energy Bills
Insulation keeps your home warmer in the winter, which lowers your heating costs. In the summer insulation keeps your home cooler, which eases the load on your air conditioner.
More Comfortable, Quieter, Living
Insulation keeps your family more comfortable by making it easier for your furnace or air conditioner to maintain a constant temperature. Insulation also absorbs sound, reducing the unwanted noise from appliances, audio equipment, conversation and other sources of sound that are transmitted through your walls and floors.
As insulation saves energy it significantly decreases the generation of harmful air pollutants to the atmosphere. Not only does fiber glass insulation contribute to cleaner air, it is an inherently "green" product in terms of assessing its environmental impact over its lifetime. Manufactured with recycled and renewable resources, every pound of insulation ultimately saves twelve times more energy than it takes to produce it. So along with greater energy savings, insulation delivers a measurable impact on our environment, reducing the amount of energy consumption and pollution.
Insulation also prevents the depletion of our natural resources. Today's fiber glass insulation contains more than 25% recycled glass and uses renewable resources such as sand.
The Way Insulation Works
Heat Flow Resistance
To maintain comfort in your home, the heat lost in winter must be replaced by your heating system and the heat gained in summer must be removed by your air conditioner. Insulating ceilings, walls, and floors decreases this heat flow by providing an effective resistance to the flow of heat.
Heat flows naturally from a warmer to a cooler space. In winter, heat flow moves directly from heated living spaces to adjacent unheated attics, garages, and basements, or to the outdoors; or indirectly through interior ceilings, walls, and floors – wherever there is a difference in temperature. During the cooling season, heat flows from outdoors to the house interior.
In most homes, walls between rooms are only marginally effective at blocking noise. Made of drywall and lumber alone, these interior or partition walls have poor Sound Transmission Class STC ratings. An STC rating is a number used to characterize the acoustic performance of a wall, floor or ceiling—the higher the STC rating, the less sound will be transmitted between rooms. By far the easiest and most economical method for controlling noise is to install insulation in the wall cavity.
A vapor-resistant membrane (commonly called a vapor retarder) attached to batt or roll insulation decreases the possibility of moisture vapor condensing to water within the structure.
Even though you need some moisture in the air you breathe, too much moisture in your home can cause problems. When moist air comes in contact with a cold surface, some of the moisture may leave the air and become liquid, or condense. If moisture condenses inside a wall, or in your attic, you will not be able to see the water, but it can cause a number of problems.
What is an R-Value?
An R-value is a rating used to measure how well insulation can resist heat flow. The higher the R-value, the greater the insulating properties and the slower heat and cold flows through it. Because insulation with higher R-values is more energy-efficient, the colder the climate, the higher the required R-value.
Different areas of the home have different recommended R-values, depending on what materials are used and how much space is available for insulation.
Frequently Asked Questions
Why hire a professional to install insulation?
Properly insulating your home really pays; Not only by reducing your utility bills but by also adding comfort and value to your home. A professional installer will save you time and money you wouldn't otherwise installing yourself. They have the specialized products and technical expertise to insulate your home quickly, making sure your home delivers the greatest comfort and highest energy savings possible. For example, a professional installer will know your proper installed R-value as well as have the latest information on building codes.
Why should I insulate my home? Insulation increases the overall comfort of a home and adds to its resale value. It keeps a home cool in the summer and warm in the winter because it resists the flow of heat. Heat is a form of energy and always seeks a cooler area. It flows out of the home in the winter and into the home in the summer. By reducing heat flow, a properly insulated home uses less energy for heating and cooling. When installed in walls, floors or ceilings, fiber glass insulation also acts as a sound absorber to reduce the transmission of sound from one room to another or from the outside.
Where should I insulate?
Typical areas to insulate are attics and outside walls. However, you should also install insulation in areas including basement walls, floors above vented crawl spaces, cathedral ceilings, floors over unheated garages or porches, knee walls, and in between interior walls, ceilings or floors for extra sound control.
If I add more insulation, do I need to remove what's already there?
There is no need to remove what you already have since R-values are cumulative. For example, if you layer two different batts of R-19 together, you get the combined R-value of both batts (R-38). You might want to consider using unfaced R-19, R-25 or R-30 fiber glass batts and laying them cross-wise to the existing insulation covering the joists.
What is the difference between fiber glass and cellulose insulation?
Fiber glass is made mostly of inorganic materials and, therefore, is naturally non-combustible; it is installed dry and does not absorb or retain moisture; and it has nearly no settling (less than 1%) which means the R-value is stable over time. In fact, it takes three times more cellulose material by weight than fiber glass to insulate a typical home. Cellulose, on the other hand, is made up of newspaper which is organic and naturally flammable (approximately 20% of the finished cellulose product is comprised of fire retardant chemicals); it is often installed damp and needs to fully dry after installation; and it can settle as much as 20% or shrink causing the R-value to deteriorate over time. Additionally, there has been very limited testing on the health and safety impacts of the chemical treatments and potential emissions from cellulose.
What types of fiber glass insulation are available?
Fiber glass insulation is available in two types: loose fill (blown in) and blanket. Loose fill insulation comes in bags. Blanket insulation comes in batts and rolls in various R-values , widths and lengths.
Does fiber glass insulation contain any recycled materials?
Fiber glass insulation typically contains 20-40% recycled glass, depending upon the manufacturing facility and product type.
Can a home be sealed too tightly?
A certain amount of fresh air is needed for good indoor air quality and there are specifications that set the minimum amount of fresh air needed for a home. An energy specialist can perform an air leakage test with a "blower door" if you are concerned. If your home is too tight, fresh air ventilation can be added.
How Much Insulation Do I Need?
The answer depends on a number of factors:
- The age of your home (if your home is more than 10 years old, you likely need more)
- How your home is built — for example, is it a single-level or multi-level structure? Do you have cathedral ceilings? Is there a basement or is your home built on a slab?
- How you heat and cool your home — do you have a furnace, a central air conditioner, or a heat pump?
Why Add More Insulation?
Adding more insulation above minimum requirements helps:
- Increase energy savings
- Provide greater noise control
- Control moisture which helps your house and roof last longer
- Savings may vary, find out why in the seller's fact sheet on R-values.
How Much Insulation Do I Already Have?
If your home was built before energy costs started to escalate, its insulation levels may now be far below today's recommendations for energy savings and comfort.
Insulating an Existing Home
To achieve the maximum thermal efficiency and comfort it is important to insulate any space were energy could be lost. For optimum energy savings and comfort, consider adding additional insulation to your home.
1. Attics & Ceilings
Fiber glass insulation in attics and flat ceilings makes the home more resistant to energy loss and lowers energy bills. To achieve R-values of R-38 and higher, two layers of fiber glass batts can be used and their R-value combined. For example, an R-19 batt added to an R-30 will yield an R-49. When installing a second layer, always use unfaced insulation. Also, it is recommended that the second layer be applied across the joists. Fiber glass or mineral wool loose-fill insulation can also be used.
Sections sometimes overlooked in homes are walls between living spaces and unheated garages or storage rooms, dormer walls, and the portions of walls above ceilings of adjacent lower sections of split-level homes.
Areas that are often not insulated are floors over unheated or open spaces such as garages or porches, floors over unheated basements and the cantilevered portions of floors. Fiber glass batts can be used in these areas. When insulating floors over unheated basements or crawl spaces, faced products should be used and vapor retarders should face heated areas and be in contact with the subfloor.