Abstract: Manually trowelling floor toppings, such as aggregate decorative stone, can be labor-intensive and costly. The present disclosure includes a power rotary trowel that includes a hub rotatably attached to an electric motor via a swivel. A plurality of arms extend from the hub, and a trowel blade assembly is attached to each of the arms. The trowel blade assemblies support an operating weight that includes, at least, a weight of the hub, the arms, the electric motor, the swivel and the trowel blade assemblies. A ratio of the operating weight to a combined trowel blade assembly length is less than 1.3 pounds per inch.