Types of Edgers and Groovers
There are a wide selection of specialized finishing tools designed to help give the slab its final shape in that very short window when freshly placed concrete is hardening. Finishers can match tool types, shapes, and even metal compositions to quicken their performance of specific tasks or jobsite conditions and craft a quality project.
Edging pros use tools specifically designed to shape and consolidate the corner of a concrete slab, be it a driveway, a curb or even a stub column. The finishing action prevents the edges from chipping with wear.
Radius edgers are the basic tools for cornering driveway slabs. They normally have a 6" long blade with one side bent to a specific radius and a specific lip dimension. Manufacturers offer a wide range of tools with unique radius and lip combinations. Finishers can select the right geometry based on the slab’s thickness.
Finishers are often tasked to craft a corner between a slab and a vertical rise. Radius inside curb tools are designed to form curbs, corners, and inside steps. One of the tool’s lips extends upward from the slab surface to form the vertical surface inside of the step.
There are also edging tools designed for finishing cast-in-place concrete steps. Normally step edgers come in matched sets that include an inside tool for the cove and outside tool for the step nose. Since stair layout can vary depending on the project, finishers select a set with the design dimensions to craft the particular edge radius and stair riser.
For handwork on small paving projects, finishers can opt for a curb and gutter edging tool. These tools are designed to match common pavement details and are usually a combo tool. Most are a 4" wide edge tool for forming a pavement or sidewalk surface. This curb tool creates a 2" downward radius on the top edge of a concrete slab that leads into a 6" (vertical) batter edge forming the face of the curb. At the bottom of the face the tool bends outward on a 2" radius, forming the base of the gutter.
A chamfer tube edger is designed to craft smooth radius flat surfaces formed on top of round columns, such as stub piers, posts, and light pole bases. They’re commonly made with bronze to help finishers negotiate the varying wetness of the enclosed concrete. The standard chamfer tube edger leaves a 1" lip and a 1/2" radius on the formed unit.
A groover, or jointer, comes in sizes that match the slab’s area, and are designed to be used at various orientations to the slab. Some groovers are designed for close handwork, other’s for long lines. Thus, groover tool sizes range from 2" to 4-3 ⁄4" in width, and from 3" – 9" in length.
The key part of a groover is the bit. This projection on the bottom of the tool creates the groove’s depth and width. Bit depth must be paired with slab thickness, thus range from 3 ⁄16” to 2". When slab thicknesses are greater than 4", most contractors opt to saw cut the joints. Remember, the formula for a joint’s depth is 1/4 of the slabs total thickness. So a 4" slab needs a 1" joint.
Groover widths are selected based on several factors. It is important to know the look you are going for before buying a new groover. These looks are influenced by aesthetics, drainage, and whether the joint will be filled later. Accordingly, bit widths are available from 1 ⁄8" to 3 ⁄4". Several manufacturers offer groover attachments designed for bull floats and fresnos.
There are special hand groovers for crafting vertical joints in the face of concrete slabs, curbs, or steps while forms are in place. The tool is inserted just behind the form leaving a long, narrow vertical joint.
These finishing tools serve as an extension of the finishers hand on the concrete. Thus, finishers often have several of the same tool design, but in different metal types and configurations.
Let’s look at two important finishing tools: edgers and groovers
Edgers
Edging pros use tools specifically designed to shape and consolidate the corner of a concrete slab, be it a driveway, a curb or even a stub column. The finishing action prevents the edges from chipping with wear.Radius edgers are the basic tools for cornering driveway slabs. They normally have a 6" long blade with one side bent to a specific radius and a specific lip dimension. Manufacturers offer a wide range of tools with unique radius and lip combinations. Finishers can select the right geometry based on the slab’s thickness.
Finishers are often tasked to craft a corner between a slab and a vertical rise. Radius inside curb tools are designed to form curbs, corners, and inside steps. One of the tool’s lips extends upward from the slab surface to form the vertical surface inside of the step.
There are also edging tools designed for finishing cast-in-place concrete steps. Normally step edgers come in matched sets that include an inside tool for the cove and outside tool for the step nose. Since stair layout can vary depending on the project, finishers select a set with the design dimensions to craft the particular edge radius and stair riser.
For handwork on small paving projects, finishers can opt for a curb and gutter edging tool. These tools are designed to match common pavement details and are usually a combo tool. Most are a 4" wide edge tool for forming a pavement or sidewalk surface. This curb tool creates a 2" downward radius on the top edge of a concrete slab that leads into a 6" (vertical) batter edge forming the face of the curb. At the bottom of the face the tool bends outward on a 2" radius, forming the base of the gutter.
A chamfer tube edger is designed to craft smooth radius flat surfaces formed on top of round columns, such as stub piers, posts, and light pole bases. They’re commonly made with bronze to help finishers negotiate the varying wetness of the enclosed concrete. The standard chamfer tube edger leaves a 1" lip and a 1/2" radius on the formed unit.
Groovers
Groovers cut straight-line depressions into a fresh concrete slab for crack control. As the concrete contracts during drying, the depression creates an intentional weak area that attracts cracking in the base of the groove. There is a definite formula to follow when calculating joints. The depth of the groove should be about one-fourth the thickness of the slab. Most residential concrete, such as sidewalks, driveways, and patio are nominally 4" thick, thus grooves should be 1" deep for effective crack control.A groover, or jointer, comes in sizes that match the slab’s area, and are designed to be used at various orientations to the slab. Some groovers are designed for close handwork, other’s for long lines. Thus, groover tool sizes range from 2" to 4-3 ⁄4" in width, and from 3" – 9" in length.
The key part of a groover is the bit. This projection on the bottom of the tool creates the groove’s depth and width. Bit depth must be paired with slab thickness, thus range from 3 ⁄16” to 2". When slab thicknesses are greater than 4", most contractors opt to saw cut the joints. Remember, the formula for a joint’s depth is 1/4 of the slabs total thickness. So a 4" slab needs a 1" joint.
Groover widths are selected based on several factors. It is important to know the look you are going for before buying a new groover. These looks are influenced by aesthetics, drainage, and whether the joint will be filled later. Accordingly, bit widths are available from 1 ⁄8" to 3 ⁄4". Several manufacturers offer groover attachments designed for bull floats and fresnos.
There are special hand groovers for crafting vertical joints in the face of concrete slabs, curbs, or steps while forms are in place. The tool is inserted just behind the form leaving a long, narrow vertical joint.
Factors When Purchasing Edgers and Groovers
These finishing tools serve as an extension of the finishers hand on the concrete. Thus, finishers often have several of the same tool design, but in different metal types and configurations. -
- Not all concrete feels the same when finishing. Sometimes the mud feels smooth as cream, and then the next day the same mix feels sticky. Some blame cement, but often the weather has a lot to do with the difference. Some finishers prefer stiffer tools, while some prefer more flexible ones.
- The type of sand and fiber in the mix can also influence tool selection. When sand is graded from crusher fines, it tends to be more angular and causes the tool to drag. Natural sand is more rounded, allowing easier tool movement. Some sands are more abrasive, wearing tools faster. Fibers also can influence selection. Polypropylene fibers can cause a concrete to be sticky, and steel fibers in concrete may require a heavier tool to work on grooves and edges.
- Tool manufacturers also offer “walking” tools. These tools are attached to brackets on long wooden handles. Edgers are easily bolted to these attachments. Finishers can opt for two styles of attachment brackets. One style allows flipping of the handle from one side to the other allowing the finisher to easily change positions on long straight lines. A bracket design includes a swivel. This feature allows the finisher to lock in the attachment to the handle to groove or edge at any point in a 360-degree radius.
- Edgers are available with front and back ends that are either flat or curved upward to aid the finisher’s actions. These add-ons can prevent the tool from gouging the concrete. Finishers can choose from a wide array of handle styles on both edgers and groovers. Most tools come standard with wood handles and many manufacturers offer comfort-grip handles with a softer grip that helps reduce hand fatigue. Try the feel of the handle with your work gloves before purchasing, checking the distance between the blade and your knuckles for adequate space.
- When selecting a tool, it’s important to choose the right metal composition. This selection is often based on tool application.
- Not all concrete feels the same when finishing. Sometimes the mud feels smooth as cream, and then the next day the same mix feels sticky. Some blame cement, but often the weather has a lot to do with the difference. Some finishers prefer stiffer tools, while some prefer more flexible ones.
One thing that dictates pricing differences among tools is the type of steel used for the blade. The most common type of material is blue steel, a treated material that is resistant to rusting. Blue steel is thin and lightweight, so it flexes slightly under hand pressure.
The next level of tools feature stainless steel which does not rust and is often slightly stiffer than blue steel. Some stainless-steel tools come with highly polished finishes, so they glide more easily through the concrete.
And for locations where the sand is abrasive, manufacturers offer high-carbon steel which also does not rust but has longer edge life due to its high resistance to abrasion.
Many tools are also available in bronze, a material that is extremely durable. Bronze edgers are usually heavier and thicker, producing a smoother, denser edge, often making them worth the extra investment.