A pressure joining method includes a hammer drill attachment device mountable within the chuck of a hand-held hammer drill. Using the hammer drill attachment, an operator installs flooring sheets onto a hook and loop flooring subfloor. The hammer drill attachment includes a shaft for mounting the attachment within the chuck. The hammer drill imparts vibration to the shaft when operated. An angled body member is attached to the shaft and extends downward toward a foot assembly having a foot pad means. The foot assembly vibrates when the hammer drill is actuated to cause the foot pad means to abut against the overlapping sheets of a flooring system and to press the sheets onto an underlying subfloor, thereby forming a seam between the edges of the floor sections.