• Where there are small concealed spaces over rooms, provided the space does not exceed 50 square feet, or 4.6 square meters.
• In spaces formed by sets of facing studs or solid joists in walls, floors, or ceilings where the distance between the facing studs or solid
joists does not exceed 6 inches, or 15 centimeters.
page 5 574-709 Rev. AP
4098 Detectors, Sensors, and Bases Application Manual