Indoor air quality has become a major issue due to recent conservation efforts to reduce the cost of heating and cooling buildings, increased reliance on mechanical ventilation equipment, and growing awareness that air quality problems can impact the health, comfort, and productivity of building occupants. Since 1974, in the wake of the first oil embargo, the need to reduce building maintenance and operation costs has been a priority of building managers. To reduce these costs, new buildings have been constructed as hermetically sealed structures. Additionally, older buildings have been sealed by the addition of energy-efficient window and door closures. As a result, fresh air ventilation is provided primarily by way of mechanical air-handling equipment. [Read more…]
The concern regarding asbestos and health risk evolved quickly in the early 1980’s and resulted in a blizzard of standards and regulations. The very first federal standard that applied to building owners and operators was proposed by EPA in 1980 and promulgated in 1982. The standard is known as 40 CFR 763, Friable Asbestos-Containing Materials in Schools, and specifically targets schools as the name implies. The standard required public and private educational authorities (K-12) to inspect their buildings for friable ACM, sample the buildings to determine asbestos content, and assess the potential hazard. [Read more…]
Asbestos is a ubiquitous mineral product that has been widely used for more than one hundred years. It has been used in numerous building products, including thermal insulation (pipes, boilers, water tanks), fireproofing, acoustical plasters, and an enormous number of miscellaneous products, including floor tiles, ceiling tiles, textiles such as gloves and blankets, vehicle brake and clutch linings, and various roofing and siding materials. It wide use was due to its superior insulating characteristics, fire resistance, chemical resistance, tensile strength, and abundance. [Read more…]
While asbestos products were widely used in building construction since the early 1900’s, the recognition of health hazard evolved slowly. The occupational hazard of asbestos was identified in the 1930’s in Great Britain and was recognized in the medical literature in the United States by World War II. The occupational disease asbestosis was the first asbestos disease recognized in the medical literature and was cited in the Worker’s Compensation laws in many states in the US. It took much longer to recognize the cancer mesothelioma, since it tends to have a long latency period. As stated in the National Cancer Institute paper, “Also, very high exposures, which were likely to have occurred in the 1930’s and 1940’s, may have resulted in lung cancer or asbestosis before mesothelioma could develop.” [Read more…]
We have discussed mold activity at length regarding water intrusion and mold growth in basements. As we know, crawlspaces are also under the house, but are a different beast altogether. The lower building areas, such as basements and crawlspaces, most frequently develop mold amplification. We know that moisture is the limiting factor in mold growth.
So the question is: Should I vent my crawlspace or seal it up?
Historically, crawlspaces were vented by definition. Our most frequent finding has been that the ventilation is inadequate or somehow impaired. We wanted ample cross ventilation to capture and remove moisture that originated at floor level. We also recognized that because that meant bringing in outside air, there was the potential for moisture, either liquid or very high humidity, to be drawn into the space and increase the moisture load in the space. [Read more…]