Ask an Expert is an occasional feature where we pose a question submitted by a reader to our Healthy Home Director Carl Grimes, HHS, CIEC
Reader Question: How do I rid our home of “new construction” smell?
The “new construction smell” you are asking about is the combination of the entire mixture of chemicals “evaporating” from new paint, sealants, flooring, sheetrock, wood, and other building materials. They are properly called VOCs – Volatile Organic Compounds.
The most effective action is to remove the source of the VOCs. If the source is gone there is no more unpleasantness or other reaction. Source removal, in this case, isn’t possible because the source is the house itself! So, the next best action is to reduce the sources. If this isn’t sufficient (based on a scale of your individual reactions ranging from “nuisance” all the way to “debilitating), then the only remedy may be to remove yourself from the source. In other words, move to another house.
Reducing the sources of “new construction” VOCs, rather than removal, can often be achieved with a “bake-out.” The idea is to warm the entire house structure to speed up the out-gassing (evaporation) of the chemicals from the building materials and finishes. Think of how long it would take a pan of water sitting on the counter to empty by evaporation. Then how much faster it would occur if you put it on a warm burner on the stove. It would still take a while but it would happen faster than just sitting on the counter at room temperature. This is what a “bake-out” does to a house.
The following are general instructions that should apply to most situations.
- Close up the house and turn up the heat to 85-90 F. Leave it on all day and all night for 3-5 days. It is equally important to air out the house by opening a door and some windows for 15-25 minutes at least twice a day, three times is better. This will allow for the indoor air to be exchanged with the outside air.
- It takes at least a day, depending on the outside temperature, for the heated air to also heat the contents, materials, and structure of the house. Two or more days at the elevated temperature is needed to achieve a reduction. As the chemicals evaporate into the air the air can only absorb so much. If the “loaded” air isn’t ventilated to the outside, and replaced with outdoor air, then the chemicals can begin to be absorbed back into the contents, materials, and structure.
- After the 3-5 days are up, turn off the heat and ventilate thoroughly by opening windows and doors. Let the house cool for at least 24 hours before re-entry.
- Evaluate your experience in the house to determine if the “bake out” was successful, “good enough,” or needs more work. If it needs more work then repeat the “bake-out.”
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