You are here:
EFFECTIVENESS OF RADON CONTROL FEATURES IN NEW HOUSE CONSTRUCTION - SOUTH CENTRAL FLORIDA
Citation:
Fowler, C., S. McDonough, AND A. Williamson. EFFECTIVENESS OF RADON CONTROL FEATURES IN NEW HOUSE CONSTRUCTION - SOUTH CENTRAL FLORIDA. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/R-96/044 (NTIS 96-177761), 1996.
Impact/Purpose:
information
Description:
The report gives results of a study to evaluate the effectiveness of two slab types (monolithic and slab-in-stem wall) in retarding radon entry in new homes built in accordance with the State of Florida's proposed radon standard for new construction over high radon potential soils. Fourteen houses were monitored during their construction on sites whose soil gas radon concentrations were screened to be >1000 pCi/L. Some of the house sites had concentrations >12,000 pCi/L. Slab integrity was monitored over time, and post-construction ventilation and radon entry were measured in all the houses. The houses with slab-in-stem wall foundations exhibited more slab cracking than those with monolithic slabs. Those houses also had higher average radon entry rates, radon entry velocities, and concentration ratios than the monolithic slab houses. Both slab types proved to be effective in retarding radon entry, especially when penetrations were properly sealed. Six of the houses had post-construction average indoor radon concentrations of <2 pCi/L; six had average concentrations of 2-4 pCi/L; and two had average concentrations >4 pCi/L. One of the two houses with elevated indoor radon concentrations was on the site with the highest soil radium content (averaging 13.9 pCi/g), radon flux measurements through the compacted fill soil (6.1 pCi/sq ms), and sub-slab radon concentrations.