Why Replace Concrete with Pavers
A worn, cracked concrete walkway creates tripping hazards, collects standing water, and signals neglect to visitors. Replacing that old slab with concrete pavers transforms the walkway into a durable, visually interesting feature that can last decades with minimal upkeep. Pavers offer distinct advantages over poured concrete. Individual units move independently, so freeze-thaw cycles cause far less damage. A cracked paver can be lifted and replaced without patching the entire walkway. The range of colors, shapes, and laying patterns lets you create a surface that complements your home’s architecture and landscape.
The key to a successful paver walkway lies almost entirely below the surface. Proper base preparation accounts for roughly 75 percent of the work, and it is the step that separates installations that last from those that settle, shift, or heave within the first few years. This article walks through a systematic approach to achieving a stable, long-lasting paver walkway, from demolition of the old concrete to the final sweep of joint sand.
Evaluating and Preparing the Site
Soil Assessment
Before placing any gravel, evaluate the soil beneath the walkway. Clay, silt, and organic soils retain moisture, remain unstable under load, and are highly susceptible to frost heaving in cold climates. A simple field test can identify problem soils. Take a handful of moist soil from the excavation and try to pack it into a ball. If it sticks together and holds its shape, the soil contains too much clay or silt and must be removed. Sandy or gravelly soils that crumble easily provide adequate drainage and a stable subbase.
For unsuitable soils, excavate to a depth of about 8 in. below the finished paver surface. Replace the removed material with well-draining granular fill such as processed 3/8-in. to 3/4-in. crushed stone. This replacement layer provides a uniform, compactable base that resists moisture retention and frost movement. A well-built walkway naturally connects outdoor living spaces and creates a cohesive landscape.
Excavation and Grading
If the native soil is suitable, excavate to a depth of 8 to 10 in. below the finished walkway surface, accounting for 4 to 6 in. of base stone, 1 in. of bedding sand, and the paver thickness. Comb through the exposed soil with a pick and remove any stones larger than 3 in. in diameter.
Grade the excavated area with a slight slope away from adjacent structures. A minimum cross-slope of 1/8 in. per foot ensures surface water drains off the walkway rather than pooling or running toward the foundation.
Tree Root Considerations
Tree roots present a unique challenge for paver walkways. As roots grow, they exert enough force to lift and displace pavers. Walkways beneath mature tree canopies are almost certain to encounter large roots. The best strategies are to route walkways away from trees, remove problematic trees, or accept periodic releveling of heaved pavers. Cutting major roots to accommodate a walkway can destabilize the tree without consultation with an arborist.
Building the Base Layer
Base Material Selection
The base layer is the backbone of a paver installation. It distributes the load of foot traffic and seasonal frost forces across the soil below. Processed crushed stone with angular faces performs far better than rounded gravel because the angular particles lock together under compaction, creating a mechanically stable mass. The recommended gradation is 3/4-in. to 3/8-in. crushed stone, sometimes called road base or class 5 aggregate. Avoid using decomposed granite or limestone screenings as the primary base material; these contain fines that can retain moisture and lead to frost heave.
| Base Material | Compaction Quality | Drainage | Frost Resistance | Recommended Use |
|---|---|---|---|---|
| 3/4-in. crushed stone | Excellent (angular particles lock) | Very good | Excellent | Primary base for walkways and patios |
| Class 5 road base | Very good | Good | Very good | Heavy-duty base under pavers |
| Pea gravel (rounded) | Poor (particles shift) | Excellent | Poor | Not recommended as base layer |
| Decomposed granite | Fair (fines reduce stability) | Fair | Poor | Walking paths only, not for pavers |
| Sand alone | Poor | Fair | Poor | Not recommended as base layer |
Base Installation and Compaction
Spread the crushed stone in two lifts rather than placing it all at once. A single thick lift cannot be compacted uniformly. Place the first 3-in. layer, spread it evenly, and compact it thoroughly with a plate compactor. Make at least three passes over the entire area, overlapping each pass by half the width of the machine. Then place the second 3-in. lift and repeat.
For walkways narrower than 3 ft, a 12-in. plate compactor provides adequate coverage. Wider walkways benefit from an 18-in. or 24-in. machine. Keep the compacted base at least 1.5 in. below the finished paver height to allow for the bedding sand and paver thickness.
Moisture content affects compaction quality. Stone that is too dry does not consolidate fully; stone that is too wet can shift under the compactor. The ideal moisture content leaves the stone feeling damp without visible standing water. On dry days, mist the stone lightly with a garden hose before compacting.
Edge Restraint Installation
Edge restraints prevent the pavers from shifting laterally over time. Without them, outer pavers gradually drift outward under foot traffic and freeze-thaw cycles. Install rigid plastic or concrete edge restraints along both sides after the base is compacted but before placing the bedding sand. Drive 12-in. galvanized spikes through the restraint flanges at 12-in. intervals. The top of the restraint should sit slightly below the finished paver height so it remains hidden.
At transitions such as driveways or garage aprons, use a concrete curb or a heavy-duty aluminum edge restraint rated for vehicular traffic. Walkway-only sections can use standard plastic restraints, which are easier to cut and bend around curves. For a cohesive landscape look, consider pairing the walkway with a matching stone wall or garden border.
Bedding Sand and Paver Installation
Bedding Sand Preparation
The bedding sand layer serves two purposes. It provides a smooth, level surface for the pavers to rest on, and it allows the installer to make fine adjustments to paver height during placement. Use washed concrete sand with a particle size of 1/8 in. or smaller. Do not use mason’s sand or play sand, which contain too many fines and can wash out or retain moisture.
Spread the bedding sand to a uniform depth of 1 in. after compaction. The key to achieving this uniform depth is using screed rails. Place two lengths of 1-in.-diameter metal pipe or PVC conduit on the compacted base, spaced slightly wider than the walkway width. Dump sand between the rails and screed it flat using a straight 2×4 board that rides on top of the rails. Remove the rails carefully and fill the grooves with sand, smoothing them flat with a margin trowel. Do not compact the bedding sand before setting pavers.
Paver Setting Patterns
Choose a laying pattern that suits the walkway width and the paver size. Running bond, where each row is offset by half a paver length, works well for rectangular pavers on straight walkways. Herringbone patterns offer greater structural interlock and are ideal for walkways that will see heavy foot traffic or occasional vehicle loads. Basket weave patterns suit square pavers and create a classic, formal appearance. The same principles used in brick laying for floors apply here to paver walkways.
Set the pavers working from one end of the walkway toward the other. Place each paver directly onto the bedding sand without sliding it into position; sliding disrupts the sand level and creates low spots. Tap each paver firmly into place with a rubber mallet. Check for level frequently using a long straightedge laid across three or four pavers at a time. If a paver sits too high, lift it, remove a small amount of sand, and reset it. If it sits too low, lift it and add sand beneath.
Cutting Pavers
Almost every walkway requires cut pavers, especially at curves, borders, and transitions. For straight cuts, use a masonry splitter or guillotine-style paver splitter. For curved cuts or angles, use an angle grinder fitted with a diamond masonry blade. For large volumes, a wet saw with a diamond blade produces the cleanest edges and reduces silica dust exposure. Always wear a respirator and eye protection when cutting pavers. Install cut pavers last, measuring each individually because gaps at the walkway edge can vary along its length.
Compaction and Joint Sand
Surface Compaction
After all pavers are in place, including cuts, make an initial pass over the entire walkway with the plate compactor fitted with a rubber pad or paver protector attachment. The rubber pad prevents the compactor from chipping or scratching the paver surfaces. Start at one edge and work across the walkway in overlapping passes, the same technique used for the base layers. This initial compaction seats the pavers into the bedding sand and brings them all to a uniform height.
Joint Sand Application
With the pavers seated, broadcast dry polymeric sand across the entire surface. Polymeric sand contains binders that activate when wet, locking the sand particles together and preventing weed growth and insect infiltration. Pour the sand in piles and sweep it across the surface with a stiff broom, directing it into the joints. Work the sand back and forth from multiple directions to ensure complete filling.
Follow these steps for proper joint sand installation:
- Spread a generous layer of polymeric sand over the entire walkway surface.
- Use a stiff push broom to sweep sand into joints, working from multiple angles.
- Compact the walkway again with the plate compactor to vibrate sand deeper into the joints.
- Sweep additional sand into any joints that settled during the second compaction.
- Remove all excess sand from the paver surfaces. Any sand left on the surface will harden and leave a hazy film.
- Mist the walkway lightly with a garden hose to activate the polymeric binders. Follow the manufacturer’s recommended watering rate.
- Avoid foot traffic for at least 24 hours while the joint sand cures.
Final Grading and Cleanup
After the joint sand has cured, inspect the walkway for any high or low spots. Minor adjustments can be made by lifting individual pavers and adding or removing bedding sand beneath them. Check edges and transitions to ensure the edge restraints remain fully concealed and that the walkway surface meets adjacent grass or paving at a clean, finished grade. Backfill along the edges with topsoil or mulch to conceal the edge restraints and blend the walkway into the surrounding landscape. Seed or sod any disturbed turf areas to prevent erosion and give the installation a polished, professional appearance.
A well-built paver walkway requires minimal maintenance beyond occasional sweeping and an annual application of polymeric sand if joints settle. The techniques described here, from thorough base preparation to careful joint sand installation, produce a walkway that remains stable, level, and attractive for decades.