Building codes are steadily increasing the requirements for building envelope airtightness, along with mechanical ventilation. One aspect that is critical in tighter building construction is the need for maintaining a healthy indoor air environment. Outdoor pollutants entering the building include not only allergens and various chemical compounds, but also radon gas. According to the American Lung Association radon accounts for more than 21,000 deaths a year in the US. Radon has been typically abated by the use of polyethylene and air sealing under slabs and on the foundation. Radon enters the building through cracks in the foundation, and by diffusion directly through the slab and the foundation. Canadian research has developed a system using spray foam to control radon entry with both air and radon diffusion barriers. This presentation will outline the advances in radon control.

Learning Objectives:

1. Understand radon gas and the risk that is presents to the occupants.

2. Identify regions where radon is prevalent and the radon concentration level requiring mitigation.

3. Identify the various pathways that radon enters the building.

4. Understand the components of a complete radon solution.

Instructor: Randy Nicklas