Abstract: Disclosed is an integral fire protection and ceiling structure for use in a building of the kind wherein false ceilings are employed. The fire protection system comprises a rectangular gridwork of pipe sections with four-way cast pipe fittings to which the pipe sections are joined. Each fitting has a downwardly-directed outlet in which a sprinkler head is mounted. The false ceiling structure comprises intersecting support runners forming a gridwork of rectangular frames where the dimensions of the gridwork of the pipe sections are even multiples of the dimensions of the rectangular frames with the intersecting support runners being beneath and in vertical alignment with intersecting pipe sections of the pipe section gridwork. The sprinkler heads extends through the intersections of the support runners. Suspension means suspend the support runners from the grid of conduits.