Multi-family apartment buildings are becoming prevalent in testing and mitigation due to the enhanced liability to private and corporate owners. Mitigation techniques vary from outdoor powered systems, to indoor passive or powered systems. Each has its place depending on the building techniques used, and the desired outcome levels. With buildings over two stories, the complexity of any type of system increases due to the footings layout under the slab. Because of the increased building weight involved with “going up” with three+ stories, footings are typically used surrounding each apartment unit. This segregates earth-gasses into individual pockets, and necessitates the use of one draw-point per apartment unit.

Mitigation vent piping can often be run vertically through utility rooms located in each apartment, due to typical apartment “stacking” layouts, then into the attic to a manifold system layout and through the apartment roof. Depending on the radon rates per apartment, and the number of floors in the building, convection or passive (non-motorized) systems can typically be very successful in the final outcome. If post-mitigation rates are not low enough using this methodology, fans can simply be added within the attic area to accentuate system vacuum and airflow to desired levels.