A combination insert and sealant device has been designed, tested and approved that simultaneously creates and seals transverse joints in concrete pavements. The device provides a plane of darkness and automatically seals the joint in a single operation. Basically, the insert resembles a sandwich of rigid materials standing on edge with a neoprene sealing strip that encloses and seals its upper edge. The sides are coated with a coarse sand to ensure a good bond with the concrete. A removable top cap secured to the insert at the time it is installed in the concrete protects against unwanted dirt accumulation and supports the surrounding concrete during the setting period. The top surface of the cap is located one-eighth inch or less below the surface of the slab. Proper installation, which is the key to the success of the device, requires that the specified dated against the sides of the device by vibration. The necessary equipment may be purchased or rented. It includes an air-powered vibratory bull float, a gasoline powered air compressor and a power operated tapper unit for removing the cap.