Indoor air quality

Scientific evidence has shown that air inside the places we live and work can be more polluted than the air outdoors. This poses a serious health risk to occupants. Poor indoor air quality can lead to sore eyes, throat, and nose, headaches, increased susceptibility to viruses, and asthma-like symptoms. This is a concern when you consider that people spend 90% of their time indoors.

Molds are extremely common indoors and grow anywhere there is the right combination of moisture, warmth, and organic material (wood) to serve as a food source.


The key to controlling mold growth is to control moisture

The unique inert composition of RASTRA enables better control over indoor air quality. Because RASTRA does not hold or wick water like concrete block or wood, RASTRA does not promote mold and mildew.

The porous composition of RASTRA allows a slow exchange of air, which in turn allows the building to "breathe“. The exchange is slow enough that it does not allow heat or cold to escape but helps maintain good air quality, preventing "sick building syndrome." This slow exchange of air also prevents condensation that leads to mold growth. In blower door tests, a RASTRA built home tested at 0.0379 air changes per hour, or once every 26 hours. Because so much unfiltered air leaks into a wood-frame house, the interior air of a typical new wood house changes completely .5 times per hour, or once every 2 hours. This means the interior air in a RASTRA building is virtually free of airborne dust, pollen and other allergens.

Air conditioning units more effectively dehumidify indoor environments in a building with low levels of air infiltration. The solid core insulation of RASTRA is free of the voids, compressions, or thermal bypasses often associated with mold growth in wood frame construction.

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