Radon Sub-slab Suctioning System Integrated in Insulating Layer

A new principle for radon protection, using a system containing a horizontal grid of air ducts pressurised within the rigid insulation material, was presented. The principle was based on the principles for pressure reduction of the zone underneath the ground floor construction. A new element of prefabricated lightweight elements were introduced and demonstrated. The principle was demonstrated on a concrete ground slab floor with a concrete slab on top of a
thermal insulation layer above a capillary-breaking layer mounted on stable ground. The thermal insulation and the capillary-breaking layer consisted of a rigid insulation material. The new solution integrates the capillary-breaking layer and a pressure reduction zone,denoted the radon–suctioning layer, in one element. The new solution introduces the radonsuctioning layer as a horizontal grid of air ducts with low pressure to catch air and radon from the ground. The new principle was shown to be effective in preventing radon from polluting the indoor air by introducing low pressure in the horizontal grid of air ducts. A lower pressure than the pressure inside the building must be established. The element was integrated into the insulation material of the ground slab floor. The element and the insulation material were made of expanded polystyrene. The new element can be handled by one man on site.