How To Repair a Broken Stone Walkway

A cracked or broken stone walkway can be an eyesore and a safety hazard. Fortunately, repairing a stone walkway is a manageable DIY project for most homeowners. In the video above, Ask This Old House landscape contractor Roger Cook shows how to fix a cracked bluestone walkway step-by-step, from surveying the damage to applying the finishing touches.

Assessing the Damage to the Walkway

Before beginning any repairs, assess the extent of the damage to your stone walkway. This will help you determine the best course of action and the materials you’ll need for your fix.

Evaluate the Extent of Damage

Carefully inspect your walkway to determine the severity of the damage. Look for these issues:

• Cracked or broken stones
• Loose or missing stones
• Uneven surfaces
• Deteriorating mortar or sand between stones

This will impact just how hefty your repair will have to be, the right materials to buy, and the overall cost. We recommend planning for high-quality materials to make sure your fix lasts for a long time.

Identify the Type of Stone

Different types of stone may require specific repair techniques. Make sure you know which stone you need to buy to match the surrounding ones on your walk, keeping in mind coloring and thickness. Common stones used in walkways include:

• Bluestone
• Flagstone
• Granite
• Limestone
• Slate

Materials and Tools to Repair a Stone Walkway

Once you’ve surveyed the damage, get the necessary materials and tools for the repair.

Tools

• Flat pry bar
• Garden hose with nozzle
• Level
• Pointed trowel
• Push broom
• Rubber mallet
• Shovel
• Wheelbarrow
• Hand tamper
• Angle grinder with diamond masonry blade
• Circular saw with diamond blade
• Screwdriver
• Safety gear

Materials Needed

Depending on the extent of the damage, you may also need these materials:

• Replacement stones
• Polymeric sand
• Stone dust or mortar
• Water

Removing Damaged Stones from the Walkway

The first step in repairing your stone walkway is to remove the damaged stones. This process requires care to avoid damaging surrounding stones or the underlying surface.

Lift Broken Stones

Use a flat pry bar to carefully lift the broken or damaged stones. In the video, Cook demonstrates how to remove a thin piece of bluestone to reveal the underlying surface.

Clear the Area

Once you’ve removed the damaged stones, use a shovel to scrape away any existing sand or debris from underneath the stones. This creates a clean surface for the new setting bed.

When you flip a removed stone over, examine the underside closely. If you see white residue on the bottom, that tells you the stone was making full contact with the sand beneath it and has been staying damp — a key indicator that moisture has been undermining the setting bed. Also check the edges: if nothing was supporting them, that’s likely why the stone cracked in the first place. Understanding the failure helps you avoid the same problem when you reset the new stone.

Preparing the Setting Bed for Stones

A proper setting bed is the foundation for a stable and long-lasting stone walkway. The type of setting bed you use may depend on the existing surface beneath your walkway.

Mix the Mortar

If you’re working with a concrete base, as Cook discovers in the video, you’ll need to create a mortar setting bed. Mix stone dust and water in a wheelbarrow to create a wet, workable consistency.

Apply the Setting Bed

Use a shovel to spread the mortar mixture onto the concrete base. Smooth it out with a pointed trowel to create an even surface for the new stones.

Pro Tip: As demonstrated in a This Old House project, before applying the mortar setting bed, brush a bonding additive directly onto the existing concrete substrate, making sure to work it into all the nooks and crannies. This gives the new mortar something to grip. As the project mason explains: “When this mortar hits this, it has something to stick to. This additive can also be put into the mix, but I like to apply it right to the substrate of what we’re doing.”

Getting the Mix Right: According to This Old House Magazine, the ideal setting bed for bluestone uses a ratio of 12 parts stone dust to 1 part dry cement. Slowly add enough water to make a stiff mix. Spread the mix thicker than its planned final thickness, since bluestone slabs will settle into the wet mix half an inch or more depending on their size and weight. Check bed thickness by measuring the distance from the setting bed to a reference string line.

Setting New Stones

With the setting bed prepared, you can now place the new stones. This step requires precision for a level and stable walkway, so pay close attention.

Place the Stones

Carefully set each new stone into the mortar bed. Use a rubber mallet to gently tap the stones into place, making sure they’re level with surrounding stones.

Adjust the Stone Height

If a stone sits too low, lift it up and add more mortar beneath it to raise it to the proper height. Cook uses this technique in the video to achieve a flush surface with adjacent stones.

Cutting Stones to Fit

Sometimes, you may need to cut stones to fit specific spaces in your walkway. This process requires some special tools and safety precautions.

Use a Wet Saw

For precise cuts, Cook uses a circular saw fitted with a diamond-impregnated masonry blade and a water attachment. This reduces dust and provides a clean cut. Cook also uses an angle grinder with a diamond masonry blade, but that tool kicks up considerably more dust, so use it with caution. Always wear your safety gear, including a dust mask, hearing protection, and safety glasses.

Technique Tip: For straight cuts, mark the cut with a pencil on the top face, then scribe the cut-line using a carbide-tipped awl with a level as a straightedge to guide the scribe. To score the slab, set the saw blade to a ½-inch cutting depth, start the saw, and slowly guide it along the cut-line. Then set the blade to 1 inch and make another, final pass. With solid premium-grade bluestone, a scoring cut halfway or three-quarters of the way through is sufficient — just knock off the waste side with a hand sledge. A cheaper, lower-grade stone that’s prone to fracturing has to be cut all the way through.

Filling Joints Between Stones

After setting all the stones, it’s important to fill the joints between them. This step helps stabilize the walkway and prevent weed growth. Before doing so, you may need to remove any old material that’s in the spaces between stones with a screwdriver or pry bar.

Apply Polymeric Sand

After clearing the joints, use a push broom to sweep polymeric sand across the surface of the walkway, making sure it fills all the joints between stones. This particular sand hardens when wet, binding the stones together. Sweep it off the tops of the stones completely—you don’t want it to bind to those areas.

Activate the Sand

Use a garden hose to mist the entire surface lightly, activating the polymeric sand. As Cook explains, you’ll o the process twice with a 15-minute wait between applications.

Allow Time to Set

Give your repaired walkway time to fully set before using it. This typically takes 24–48 hours, depending on weather conditions and the products used.

Additional Considerations for Stone Walkways

When working with stone, there are a few other components to keep in mind. These can impact the longevity and appearance of your walkway.

Stone Thickness and Quality

Choosing high-quality stones with appropriate thickness is important. Thicker stones are more durable and less prone to cracking over time.

Cook highlights the difference between thinner bluestones and those that are 1.5–3 inches thick. Thinner stones are more vulnerable to breaking under pressure, while thicker ones provide a sturdier walking surface.

Stone Color and Finish

Stones come in a variety of colors and finishes. For instance, bluestone can range from dark blue to shades with purples, greens, and rust colors. Picking a color and finish that complement your home’s exterior will boost your curb appeal.

Note that some stones, like thermal-treated bluestones, have a smoother finish compared to natural cleft stones, which keep their natural and rugged texture.

Maintenance Tips

Maintenance can extend the lifespan of your stone walkway. Regularly sweep the surface to remove dirt and debris, which can cause wear over time. If needed, reapply polymeric sand to the joints to keep the path stable and prevent weed growth.

The base beneath your stones matters just as much as the stones themselves. As explained on Ask This Old House, the ground beneath walkways moves slowly over time, leaving hardscaping vulnerable to shifting. To keep stones in place, walkways need a deep, firm, solid base. In most installations, the ground is dug down six to eight inches depending on the thickness of the material, compacted flat to ensure a level surface, and then layered with gravel or crushed stone for drainage. This minimizes water absorption during freeze/thaw cycles — the major culprit behind walkway failures.

Future Projects

Once you’ve repaired your stone walkway, you might want to dive into more improvements that will add value and enjoyment to your outdoor space. Here are a few of our ideas.

Expand Your Walkway

Expanding your current walkway can create a more inviting entrance or connect different areas of your yard. This might involve adding new sections with matching stone types or patterns to achieve a cohesive look.

Use Landscaping Elements

Complement the beauty of your stone walkway by adding landscaping elements such as flower beds, shrubs, or ornamental trees along the edges. This gives it more dimension and blends the walkway with the natural surroundings.

Add Lighting

Installing lighting along your walkway can improve safety and create a welcoming ambiance. Options include solar-powered lights, low-voltage landscape lighting, or even decorative lanterns that match your home’s style. Thoughtfully placed lighting highlights the pathway and can set the tone for a cozy atmosphere.

Build a Patio

If you enjoy outdoor living, consider building a stone patio as an extension of your walkway. A patio provides a perfect spot for outdoor dining, relaxing, or entertaining guests. Using the same or complementary stone will create a seamless transition between the walkway and patio areas.