See demo of the Walttools 8″ Slate Border Roller
How to Use a Concrete Border Roller (Overview):
Form, pour, and place concrete as normal. Bull float and edge normally. If control joints are being placed with groover, do so as normal.
Timing is everything and rollers are used earlier than when you begin stamping. You should be able to press your thumb into the surface far easier than the standard for stamping (anywhere from 15 min to 45 min).
The ideal time is when the surface cream allows the roller to partially settle into the surface allowing a clean impression. If you begin to roll and the roller “slides/skids” instead of rolling, it is too soon. If the grout lines “support” the roller on the surface, it is too hard and you will need to lean much more on the roller, which makes a steady impression more difficult.
If you’re using a release agent (powder or liquid) of a different color than the rest of the job, care should be taken to carefully place release in the border path. One simple method is to cut a heavy-nap paint roller cover (or sponge for liquid) to the same width as your stamping border roller, coat with release, and roll the release along the intended border path. If you’re using the same color release as the remaining job you can apply your release with less discretion.
TI rollers have either one or two grout edges. Either works for borders. If you’re using a single edge roller, the plain edge is to be placed on the outside along the form where it should have been previously edged, thus giving you the second grout line.
With one hand on the bull float handle and the other on the outer edge of the bracket, carefully begin to roll the impression. With a slow/steady walking pace, keep a slight, but steady pressure on the roller, keeping it aligned along the outer form to produce the best results. When encountering a curve, move the outer hand to the roller itself to aid in manually “rolling/turning” the roller. This method will allow the tool to shape the stones or bricks into the corresponding shapes as though they were cut for the curve. If doing a double row, the same process is followed with the exception of having no form support as a guide. Added rows are recommended only by using a second roller because timing can become critical as the surface hardens.
After rolling the border, if the remaining surface is to be stamped then certain precautions should be taken to avoid damaging the completed border. Typically, when working around the border, you will protect your border with a similar texture seamless skin. Carefully place the skin on the border surface under the potential striking area of the floppy. If needed, you can gently rest the floppy over the skin, preventing any grout lines or other surface marring as you complete the impression with that mat. Care must be taken not to tamp the stamp on the actual border. Continue this method as you complete the edges of the main stamped surface.
When doing longer runs with the border roller that are not along the edge (as would be the case of masking a control joint), you will need to use a handle of the appropriate length. With a steady hand, carefully roll the roller along the groove with the non-grout edge on the groove if that is the roller design. When possible, using a long straight-edge as an edge guide is recommended for steadiness. If a metal straight-edge is not available, making an “L” brace with 2x4s will work and resist curving. Long internal runs like this need to be done before any outer borders due to the inability to provide as much downward pressure on the border roller.
Optional matching floppy mats are also very useful when working into sharp corners and up against a vertical obstruction. Touch-ups and small corrections are usually completed with a grout tool and/or touch-up mat. As with any new decorative concrete tool, it is highly recommended to use on a test slab to practice with various techniques before an actual project.