Remodeling and Renovating

Building
Actions to prevent indoor air pollution from the beginning
Preventing indoor air problems when renovating or remodeling

Building

Being involved with construction of a new building or home from the very beginning is an excellent way to prevent indoor air problems, since there are things you can do to make indoor environments healthier. Building standards for air quality, thermal comfort, lighting, acoustics, and ergonomics, statistically only addresses the needs of 80 percent of office workers and typically do not allow for individual control of environmental factors. As many as half of a building's users can be found to be dissatisfied with at least one environmental attribute in a building's design. Therefore, if you are involved from the very beginning, you can consider these things in the design.

Before you even break ground, it is very important to know about the soil under the building or house, especially if the slab is going to be in direct contact with the soil. This is because often there may have been many chemicals or there may be radon in the soil that can then get inside. There have been cases of indoor air problems in Texas, Florida, and California where the cause of the problem turned out to be contaminated agricultural lands. In addition, if fill dirt is brought in, it is important to make sure it is not contaminated. In one instance in Florida, fill dirt that was contaminated with high levels of radon was added to low-lying areas at several sites, which resulted in elevated indoor radon levels in the homes built on those sites.

The most effective way to prevent indoor air pollution is to prevent it at the source, so take steps from the very beginning in choosing building materials and furnishings that do not give off many pollutant emissions. Also, make sure that the building is sealed to save on energy, and has a good ventilation system capable of bringing in enough fresh, outdoor air.

Actions to Prevent Indoor Air Pollution From the Beginning

Here are a few important actions that can make a difference:

• Pay careful attention to roof and window design. Construction is needed to minimize moisture accumulation on the roof and leakage around the windows.

• If you are using concrete for some of your building, consider using fly ash as a substitute for some of the cement. Fly ash, which is a waste product from coal-fired power plants, can be substituted for 15 percent to 35 percent of the cement in concrete mixes according to the US Environmental Protection Agency. The benefits of doing this is that it helps with the solid waste problem and it reduces overall energy use.¹

• Though concrete is usually one of the best materials for people who are chemically sensitive, occasionally chemicals such as fungicides, germicides, and insecticides are added to the concrete; these could possibly off-gas into the home or building. To prevent these problems, make sure that the concrete used has the minimum amount of ingredients or use a sealer on the finished concrete to minimize off-gassing. However, some of these sealants may also cause health problems.¹

• The building envelope should be constructed so that there is slight positive pressure inside the building.

• Use radon-resistant construction techniques.

• Choose building materials and furnishings that will keep indoor air pollution to a minimum. For example, use solid wood floors, cabinets, and furniture rather than pressed wood that can give off formaldehyde. Also, do not stain or varnish these things inside. Either have that done before the wood products come inside or go with natural wood. Choose environmentally friendly, low maintenance and low-emitting materials.

• Upholstered interior furnishings, draperies and textiles and carpeting should be kept to a minimum because of their role as dust collectors and volatile organic compound (VOC) emitters. Make sure that good periodic maintenance procedures are put in place to keep these materials dry and to extract soil and dust from them regularly.

• Concrete floors and walls can cause moisture problems and lead to mold and mildew growth, which cause significant health problems in certain individuals. There are two common sources of moisture:

  1. Moisture wicking through concrete from the surrounding soil: To eliminate moisture from the soil, provide good drainage around it. One way of doing this is by having proper landscaping that will allow drainage of moisture away from the base of the building and minimize the likelihood of water damage and secondary pest and mold/fungal infestation and the need for pesticide treatment later. Also, put a layer of crushed stone underneath the slab, and install a polyethylene moisture barrier under the slab (protected from the concrete with a layer of sand if possible).

  2. Moisture from the house that may condense on the cold surface of concrete: To reduce the likelihood of condensation on concrete surfaces, they should be insulated. In northern climates, put a layer of rigid foam on the outside of the foundation wall and under the slab. This will generally keep the inner surface of the concrete warm enough so that condensation will not occur. With interior foundation insulation, provide a vapor barrier to keep moisture from reaching the concrete surface. In southern climates, protecting against condensation may be more difficult.

• Become familiar with mechanical ventilation systems and install one that brings in enough fresh outdoor air for each occupant. Make sure it meets the requirements of ASHRAE/ANSI Standard 62-2001, Ventilation for Acceptable Indoor Air Quality.

• Request carpet, furniture, adhesives and paints designed to limit off-gassing. Have new carpeting and other materials aired out before it is installed. Have the carpet installed with carpet tacks rather than adhesive glues.

• Try to avoid using anything that uses or needs glues, varnishes or formaldehyde in construction or installation.

• Have copper pipe plumbing installed rather than PVC pipe that is more likely to leak and create moisture problems.

• Since wet materials such as paints, adhesives, and sealants, in general, are higher emitters of volatile pollutants, use them first before bringing in dry, absorptive materials such as carpet, ceiling tile and insulated ventilation ductwork. These dry materials can absorb/adsorb VOCs from the wet materials and them re-emit them.

Preventing Indoor Air Problems When Remodeling or Renovating

Indoor air quality (IAQ) complaints occur frequently after building renovations have been completed. Solvents are often used during remodeling, which can result in persistent odor and chemical irritation complaints long after the space has been reoccupied. During some construction and in most renovations, contractors are not required to upgrade the filter removal efficiency or protect the return air ducts or plenum from excessive dust accumulations during this time. These construction dusts and vapors from chemicals being used can be carried throughout the air handler system and can contaminate surfaces. Therefore, unless remodeling and renovation are planned with IAQ in mind, these activities can create indoor air quality problems by emitting dust, odors, microorganisms and their spores, and VOCs.

Take steps to prevent these problems by doing the following before any renovations or remodeling begins:

• For offices, make sure the IAQ manager reviews the designs and construction activities for all proposed remodeling or renovation activities before they begin. There should be IAQ language in the contract with the construction firm.

• If major renovations are going to take place, have the areas tested for mold, lead-based paint and asbestos to make sure these hazards are not present. If they are, then certified abatement personnel must remove them.

• Temporarily move people out of the home or building until the work is done and the area is properly cleaned. If you cannot move them, make sure the work area is sealed off completely, including the ventilation system. In a renovation project in Walla Walla, Washington, some construction workers forgot to cover up the air-intake vents when they sprayed industrial-strength petroleum sealant on the building's façade as part of a roofing and refurbishing project. Several workers began suffering from nosebleeds and dizziness. One worker who had had a perfect attendance record before this incident developed a reactive airway disease that was so debilitating that she could no longer lift her three-year-old daughter.²

• Use specialized cleaning procedures; for example, high efficiency particulate air (HEPA) vacuums, negative ventilation in the work areas, and local exhaust to the outside.

• Change filters more frequently, especially after work is completed.

• Use work practices that minimize emissions such as wet sanding dry wall.

• Buy safer products. In the first six months after a building is built, paints, adhesives, and filling compounds are among the largest sources of indoor air pollution. If you use materials that give off low emissions then you can prevent these problems. For example, when the State of Washington constructed two buildings for state workers, they tested every product that went into the buildings including things like paint, partitions, and desks.³ Using safer furnishings is also healthier for the people who are moving customers into the renovated spaces. Some of these firms are having to provide oxygen breaks for crews moving customers into new or remodeled spaces that have strong paint, carpet and furniture odor.

• Make sure lids to solvents, such as paints, are in place when the products are not being used.

• After renovations are complete, run the ventilation system at full blast for a week, if possible, to flush out vapors and dusts. Many commercial construction projects specify that a 30-day flush out of the spaces with 100 percent outdoor air be used. In any case, 24 to 48 hours is the minimum time required for simple renovations.

• Have the entire building or house cleaned before residents return or normal business activities resume. This should include cleaning surfaces with wet wiping and vacuuming (high efficiency vacuuming for fine or potentially toxic dusts, such as lead, asbestos, or molds).

1. Cement and concrete: environmental considerations. Environmental Building News. March/April 1993;2(2).

2. Conlin M, Carey J. Is your office killing you? Business Week. June 5, 2000;(issue 3684):114-128.

3. Griffin K. When your office calls in sick. Health, January/February 1993;78-82.