Copyright Goodheart-Willcox Co., Inc. 44 Section 2 Introduction to Masonry the cut joint rather than appearing on the surface of the finished concrete. Groovers can be handheld or attached to a handle for larger surfaces. Groovers are usually about 6″ long and from 2″ to 4 1/2″ wide. The cutting edge or bits are available in depths from 3/8″ to 1 1/2″. 3.3.7 Concrete Brooms Concrete brooms are used to place a textured finish on the surface of the still pliable concrete. See Figure 3‑48. A broom finish is used on sidewalks, driveways, and other surfaces to create a slightly rough finish. The rough finish reduces the chance of slipping on the con- crete when it is damp, wet, or icy. “Brooming” the sur- face is the last step in finishing concrete. 3.3.8 Concrete Joint Saw A concrete joint saw, Figure 3‑49, can be used to cut joints in concrete slabs. The machines may be either electric or gasoline powered. They have a shatter- proof abrasive or diamond blade that produces a nar- row joint. Joints are usually cut when the concrete has hardened four to twelve hours. Most concrete saws have an option for wet cutting, which greatly reduces the sawing dust problem. A gar- den hose can be connected to the saw if the location has a water source. Using water also aids in cooling the saw blade, which lengthens its life. Marshalltown Company Figure 3‑48. A concrete broom has soft bristles so it does not cut into freshly placed concrete. This broom is 24″ wide, but brooms range in size from 18″ to 48″. Crank for raising and lowering blade Fuel tank Blade guard Gas engine Marshalltown Company Figure 3‑49. A power concrete joint saw used for large jobs. This model has an 11 hp motor and cuts to a depth of 4 5/8″. A Marshalltown Company Figure 3‑47. Two popular styles of groovers. A—Groover size is 3″ × 6″ with a cutting depth of 1/2″. B—Groover size is 4 3/8″ × 8″ with a cutting depth of 1″. This groover is made to be attached to a handle to allow for grooving areas such as driveways. B