How to Build Concrete Lawn Borders
There is no better way to add curb appeal and value to your home than adding concrete lawn borders.
Concrete borders can be used to define your lawn, flower beds and pathways, adding a clean, finished look to your home’s landscaping.
Concrete lawn borders can be poured at virtually any depth or width and can be easily formed to meet any contour. They can even be colored or stained.
Concrete is also the most durable, long-lasting edging option available. It doesn’t rot, warp or deteriorate.
Pouring concrete lawn borders is also a very affordable Do-It-Yourself project, costing less than $2 per lineal foot for all the concrete and materials you will need.
To get started, move away any landscaping materials, like mulch or landscape rock, from the perimeter of your lawn or planting beds.
Using a shovel, create an outline of the border location.
Concrete borders can be installed at ground level, to act as a mowing strip, or above ground level to hold back and separate landscaping materials from the lawn.
Concrete borders should be at least 3.5 inches thick and should extend a minimum of 2 inches deep into the ground. This is important to anchor the borders solidly in place, to prevent shifting and cracking.
Once you have determined the thickness of your border, the border height above the ground and border depth, dig a trench about 1/2 of an inch to 1 inch deeper than your border thickness, minus the depth of the border.
This will allow for variations in the terrain, as you build the forms.
The width of the trench should be excavated 2 to 3 inches wider than the width of the intended border/edging. Try to keep the walls of the trench as vertical as possible. This will help provide support for the forms, especially on curves.
Use a square shovel to level the bottom of the trench, to provide a level and compacted base.
Once the concrete border trench is excavated, you are ready to begin constructing your forms.
Quarter inch plywood is the recommended material for border forms because it can be used for both straight and curved border shapes.
Quarter inch plywood is available in 4 foot by 8 foot sheets and can be easily cut with a circular saw.
The plywood should be cut into strips equal to the depth of the concrete border. Twelve inch long, one inch by 2 inch wide wood stakes should be used to securely hold the quarter inch plywood forms in place.
First, position the form in the trench, and then, drive a wood stake into the ground, on the outside of the form. It is important to keep the stake vertical and snug, against the plywood form.
The stake should be level with the top edge of the form.
After the first stake is in place, use a cordless drill with a Philips head bit to drive 2 one-inch screws through the plywood, into the stake, from the inside of the form, one near the top of the form and the other in the middle of the form.
Then, drive a stake into the ground at the edge of the form, so that the form edge aligns with the middle of the stake. Make sure the form is vertical, and then screw the form into the stake with two screws. This will allow the next board to butt up against the previously set board, creating a continuous form.
Additional stakes should be used to help maintain the desired contour of the border form. Stakes can be used on the interior or exterior of the form, to help hold the boards vertical and in-place on the curves or straight segments.
When using a stake on the interior of the form, it is important to drive the stake into the ground, so that the top of the stake is no more than 1 inch above the bottom of the form. If the stakes are not driven deep enough, the concrete could crack directly above the stake.
Once you have completed a few sections of one side of the form, start constructing the other side of the border form.
The key to making the concrete border a consistent width is using wood spacers at regular intervals.
Spacers can be made out of 1 inch by 1 inch or 1 inch by 2 inch pieces of scrap wood, cut to the desired width. Border widths of 4 to 6 inches are the most common.
Simply slide the spacers between the two forms to keep your forms parallel. The spacers can be used temporarily, for alignment, or left permanently in place, as long as the spacers are pushed down to the bottom of the form, before pouring the concrete. If the spacers are placed too high, they can cause the concrete to crack.
Once the forms are completed, compact the ground under the form, and pour about ½ inch of all-purpose gravel between the forms. Then, spread level.
The gravel will prevent concrete from flowing underneath the forms and provide a solid base for the concrete.
Crack-Resistant Concrete is the recommended concrete mix for building concrete borders.
Crack Resistant Concrete Mix is a high strength, 4000 PSI mix, reinforced with special synthetic fibers that resist shrinkage cracking and has improved impact resistance. The mix also has a superior finish.
Crack Resistant Concrete Mix can be mixed by hand, in a wheelbarrow or mixing tub, or machine mixed in a barrel-type mixer. Properly mixed concrete should look like thick oatmeal, and it should hold its shape, when it is squeezed in a gloved hand.
Place the concrete mix into the form, using a shovel.
The surface of the concrete should be relatively flat and slightly above the form.
After placing a few batches into the form, use a wood float to consolidate and level the surface.
Work the mix back and forth, across the surface of the concrete, to remove excess concrete and smooth the surface. Then, using an edging tool, consolidate and shape the edges of the border. Several passes should be made in each direction, for a smooth finish.
Cut in control joints, using a margin trowel, about every 8 feet. Control joints should be a minimum of a quarter of the depth of the border, so about an inch deep for a 4 inch deep border.
The purpose of the control joint is to pre-determine where the concrete will crack, as it shrinks during the curing process (and if there is any ground movement).
Freshly placed concrete should be water-cured for a minimum of 3 to 5 days with a fine water mist.
Water curing can be eliminated by applying an acrylic concrete sealer, immediately after finishing the concrete.
The sealer can be applied with a roller, garden sprayer or brush. Sealing the border will also prevent staining from landscaping materials, soil and mowing.
Allow the concrete to cure and gain strength for 3 to 5 days, before removing the forms.
At 5 days, the concrete mix has only achieved about 1/2 of its ultimate strength.
Start by carefully prying away the stakes and removing the plywood forms. The tip of a pointed shovel also works well, providing leverage to lift out the forms, but be careful not to use too much force that could crack the newly placed concrete.
Once the forms have been removed, back fill with soil and replace any landscaping materials.
The addition of a concrete lawn border or edge around flower beds, lawns or other landscape areas will give your home that clean, finished look that will add curb appeal for years.