Indoor Air Quality in Homes
Remodeling Your Home? Have You Considered Indoor Air Quality?
Addressing Indoor Environmental Concerns During Remodeling
While remodeling or improving the energy efficiency of your home, steps should be taken to minimize pollution from sources inside the home, either from new materials, or from disturbing materials already in the home. In addition, residents should be alert to signs of inadequate ventilation, such as stuffy air, moisture condensation on cold surfaces, or mold and mildew growth. These issues should be addressed either before or during the remodeling process. For a discussion of basic indoor air quality in homes and how it can affect your health, see EPA's The Inside Story: A Guide to Indoor Air Quality.
Usually the most effective way to improve indoor air quality is to eliminate or control sources of pollution, or to reduce their emissions. Another important approach that goes hand in hand with controlling pollution is using mechanical ventilation to lower the concentrations of pollutants in your home by increasing the amount of outdoor air coming inside. A third strategy, air cleaning, complements source control and ventilation. These strategies are discussed both in The Inside Story, and in the information included on this site.
In general, you should address the following issues when remodeling your home.
Good Work Practices
Regardless of what part of the house your remodeling project takes place in, there are good work practices that you can use to help minimize or prevent indoor air and other indoor environmental problems. Read more about Good Work Practices.
Read about Best Practices
- Moisture Control
- Combustion Appliances
- Air Ducts
- Energy Efficient Improvements
- Pest Control
- Volatile Organic Compounds (VOCs)
Test your homes for radon. Radon is the second leading cause of lung cancer in the U.S. You can't see or smell radon, but it's not hard to measure the level of radon in your home. Testing is easy and should only take a little of your time. For more information, see EPA's Radon Page, the publications A Citizen's Guide to Radon, the Home Buyer's and Seller's Guide to Radon and the Consumer's Guide to Radon Reduction.
EPA recommends fixing your home if a test shows radon levels in your home exceed the action level of 4 picocuries per liter of air (pCi/L). If you are building an addition (or a new home!) there are radon-resistant new construction techniques you can use to help prevent high radon levels.
Old lead-based paint is the most significant source of lead exposure in the U.S. today. The dust and chips from lead-based paint are dangerous when swallowed or inhaled; children and pregnant women are especially at risk. Harmful exposures to lead can occur when lead-based paint is improperly removed from surfaces by dry scraping, sanding, or open-flame burning, or by demolition. A home built before 1978 is likely to have surfaces painted with lead-based paint. Learn more about protecting yourself and your family from exposure to lead.
Too much moisture in a home can lead to mold, mildew, and other biological growth. This in turn can lead to a variety of health effects ranging from more common allergic reactions, asthma attacks, and hypersensitivity pneumonitis, to death. Excess moisture can be in the form of high relative humidity, leaks in the roof, walls, or plumbing, air moving from the inside or the outside into the walls, or from the basement or crawlspace. Methods to control moisture include fixing any water leaks; providing ventilation in the home; air-sealing; properly using vapor barriers in wall construction, roofs; and preventing soil moisture from entering the home through basements and crawlspaces. Read more about moisture control.
Good ventilation is important because it protects both your health and your home. Good ventilation protects you and your family from unpleasant odors, irritating pollutants, and potentially dangerous gases. Well-planned ventilation also helps prevent the growth of mold and mildew, which can cause allergic reactions and aggravate lung diseases such as asthma. Ventilation is important both during renovation and also as long as you occupy the home. Remodeling may present an opportunity to ensure your home has adequate ventilation. Read more about ventilation.
Asbestos is the name of a group of naturally-occurring minerals that separate into strong, very fine fibers. The fibers are heat-resistant and extremely durable, and, because of these qualities, asbestos became useful in construction and industry. In the home it may or may not pose a health hazard to the occupants, depending on its condition. When it can be crushed by hand pressure or the surface is not sealed, to prevent small pieces from escaping, the material is considered FRIABLE. In this condition fibers can be released and pose a health risk, such as lung cancer from inhaling the fibers. However, as long as the surface is stable, not damaged, and well-sealed against the release of its fibers and not damaged, the material is considered safe until damaged in some way.
To learn more about asbestos, including how to identify it, and how to protect those in your home during a remodeling project, read EPA's Asbestos in the Home: A Homeowner's Guide (EPA 910-K-92-001, 1990). This booklet responds to frequently asked questions about asbestos and provides information to help the homeowner make informed decisions about its care and maintenance. See also www.epa.gov/asbestos
Combustion appliances are those which burn fuels for warmth, cooking, or decorative purposes. Typical fuels are gas, both natural and liquefied petroleum (LP); kerosene; oil; coal; and wood. Examples of combustion appliances include space heaters, ranges, furnaces, fireplaces, water heaters, and clothes dryers. These appliances are usually safe. However, under certain conditions, these appliances can produce, and release into the home, combustion pollutants that can damage health or even kill. In addition, unvented or improperly vented appliances can add large amounts of moisture to the air, potentially resulting in both biological growth, and damage to the house. Proper sizing, installation, inspection, and maintenance of combustion appliances are extremely important. Providing good ventilation can also reduce exposure to combustion pollutants. Read more about combustion appliances.
Ducts should be tightly sealed to reduce air leakage. This is achieved by carefully sealing all duct seams and joints. (Note that standard cloth duct tape is not a suitable duct sealant material.) This can save energy and prevent contaminants from entering ductwork and circulating through the home. Air-sealing of ductwork also helps to balance the pressure of airflow through the ducts, preventing unplanned negative or positive pressures in the house that can lead to other problems. For example, leaky return ducts can create negative pressures which may lead to radon problems or combustion equipment backdrafting (see information on radon and combustion safety). Remodeling may present an opportunity to seal ducts that would otherwise be difficult to access.
During the actual renovation work, air duct registers in the area being renovated should be sealed during activities that will generate a lot of dust or debris. This can be done by taping plastic over the registers. Before the project is started, you should decide on a ventilation strategy to remove pollutants from the work area and prevent them from moving to other areas of the home (see good work practices for more information).
Some people consider cleaning air ducts either as part of a renovation, or because they may be "dirty". Knowledge about air duct cleaning is in its early stages, so a blanket recommendation cannot be offered as to whether you should have the air ducts in your home cleaned. EPA urges you to read Should You Have the Air Ducts In Your Home Cleaned if you are thinking about having your air ducts cleaned.
Energy Efficiency Improvements
Tight energy-efficient homes save energy and money. And with proper mechanical ventilation, they can have better indoor air quality than a leaky home. One reason is reduced condensation which could lead to mold growth. Another reason is control. In a leaky home, outdoor air enters the house — through cracks, unsealed joints, and penetrations, for example — intermittently, depending largely on the weather. Some times there will be too much leakage, resulting in a drafty house. Other times there won't be enough, resulting in a stuffy house. Mechanical ventilation in a well-insulated, well-sealed house, however, can exhaust pollutants and bring in outdoor air in a planned way. This makes a house both comfortable and energy efficient. For more information see EPA's Energy Star Home Improvement Program.
Pests can be a health hazard to you, your family, and your pets. For example, cockroaches and dust mites have been associated with asthma. However, pesticides can also be problematic. Fortunately, there are effective pest control methods that don't rely on heavy pesticide use. Pests seek places to live that satisfy their basic needs for air, moisture, food, and shelter. The best way to control pests is to try to prevent them from entering your home in the first place. You can do this by removing the elements that they need to survive. Remodeling and renovation offer opportunities to take the actions to prevent indoor pest problems. Read more about Integrated Pest Management.
There are many factors to consider before beginning a painting project, including whether existing paint is lead-based, the type of paint selected, providing ventilation while painting, and clean-up and storage of paint and painting supplies. Read more about painting and remodeling.
Volatile Organic Compounds (VOCs)
Pressed wood products, adhesives, and many finishes (such as paints and varnishes) contain volatile organic compounds (VOCs) which off-gas in varying amounts over time. Minimize the use of building products containing formaldehyde or other VOCs within the conditioned space of the house. Read more about Volatile Organic Compounds.