A modular tool for imparting profile characteristics into fluent cementitious material. The tool has an elongated base forming a permanently fixed blade, and at least one handle. The blade is configured to act as a dovetail to which any of several modular blades may frictionally fit in removable fashion. The fixed blade forms a deflector disposed to deflect removed cementitious material away from the handles. Other blades may fit by peg and socket engagement. The tool may have detachable rollers enabling the tool to advance at a controlled elevation along a wall being formed and shaped. A slide block may be arranged to engage the rollers so as to adjust their position on the tool. The tool may have integral bubble levels.