Abstract: A tri-joint groover or trowel assembly for finishing a concrete surface includes an elongate handle, a base member and a connector assembly for selectively connecting the handle to the base member. The base member has opposed edge portions and a centrally disposed longitudinal axis extending therebetween. The trowel assembly further includes an elongate track preferably having opposed sidewalls extending upwardly from the base member and extending along the longitudinal axis with the opposed sidewalls forming an opening therebetween. The base member includes a groove formed therein and substantially aligned with the opening of the track so that the connector assembly can be slidably moved therealong. The trowel assembly further includes an elongate grooving member integral with the connector assembly and extending substantially parallel to the opposed edge portions and downwardly from the base member with the grooving member being slidably movable along the groove.