How To Repair Sandstone Steps

Sandstone steps can add a rustic charm to any home, but over time, they may require repair due to wear and tear. This Old House mason Mark McCullough demonstrates the repair process on a set of sandstone steps in Dallas, Texas, showcasing techniques to fix loose stones and restore the steps’ integrity. This guide will walk you through the process of repairing sandstone steps, ensuring they remain safe and visually appealing. 

*Unless otherwise noted, costs in this article reflect an average of prices that our team found from hardware stores like Lowes and Home Depot, and on Amazon.com.

Understanding Sandstone

Sandstone is a popular choice for outdoor steps due to its natural beauty and durability. Composed mainly of sand-sized mineral particles, this sedimentary rock stands out for its unique characteristics:

• Rustic appearance: Offers a timeless aesthetic that complements both modern and traditional architecture
• Earthy color palette: Features a range of colors, from light tan to soft reds, providing an inviting look
• Versatility: Suitable for various applications such as patios, walkways, and pool surrounds, in addition to steps
• Affordability: More cost-effective than many other natural stone options
• Weather resistance: The ability to endure different weather conditions makes it particularly ideal for outdoor use

Common Issues with Sandstone Steps

While sandstone is robust, it can still suffer damage over time, especially in high-traffic areas. 

• Loose or wiggling stones from deteriorated mortar or poor installation
• Cracked or chipped stones from weathering or heavy impact
• Deteriorating mortar joints from age and environmental exposure
• Flaking or spalling surfaces from water freeze-thaw cycles 

The damage present in the video was likely a result of deteriorated mortar due to poor installation.

Tools and Materials Needed for Sandstone Step Repair

Before you start the repair process, gather everything you’ll need. 

Tools

• Brick trowel
• Bucket
• Concave jointer
• Grout sponge
• Margin trowel
• Masonry brush
• Masonry chisels
• Mason’s hammer
• Paintbrush
• Soft cloth

Materials

• Concrete additive
• Mortar mix
• Replacement sandstone
• Waterproof sealant (optional but recommended)

Step-By-Step Sandstone Step Repair Process

Follow these steps to repair your sandstone steps effectively:

1. Assess the damage: Check each stone to determine which ones are loose or damaged. Mark the stones that need to be removed or repaired.
2. Remove loose stones: Using a hammer and chisel, carefully chip away at the mortar joints until the stone is easily removable. Avoid prying to prevent breakage.
3. Remove extra mortar: Chip away the mortar beneath and around the removed stone, which will let you replace the stone at a uniform height with those around it.
4. Clean the area: Use a masonry brush to remove dust and debris. Dampen the surface with water to stop the old material from absorbing moisture from the new mortar.
5. Apply concrete additive: Spread a concrete additive over exposed areas with a paintbrush to improve bonding between old and new materials.
6. Prepare the mortar: Combine water and mortar mix in a bucket until you achieve an oatmeal-like consistency.
7. Apply mortar: Use a margin trowel to pack mortar into joints and create a bed for the stones. Create furrows every half-inch or so for better adhesion.
8. Replace stones: Back-butter the sandstone with mortar and set it in position. Press down and wiggle slightly to remove air bubbles and excess mortar. Tap the stone into place with the back of the trowel.
9. Fill joints: Pack mortar around the replaced stones, ensuring all gaps are filled.
10. Texture the surface: Use a paintbrush to lightly drag across mortar joints, bringing aggregate to the surface for a rustic look.
11. Clean and finish: Use a damp sponge to smooth the edges of mortar joints and remove excess from stone faces. Finish with a waterproof stone sealant.

Allow the mortar to set according to manufacturer instructions before using the steps.

Tips for a Successful Sandstone Step Repair

To look out for common pitfalls and give you the best chance of a professional-looking repair, consider these tips:

• Avoid damaging surrounding stones or mortar joints during repair.
• Maintain uniformity in the height and alignment of steps.
• Allow appropriate drying time.
• Match new mortar closely with existing joints in both color and texture.

Preventing Future Damage to Sandstone Steps

Post-repair efforts can prevent future damage and prolong the life of your sandstone steps. Be sure to reapply the sealant every few years to shield against moisture and staining. Regularly remove dirt and debris buildup with gentle cleaning agents to maintain the appearance, and repair any new cracks or loose stones immediately to prevent worsening. Finally, steer clear of abrasive cleaning substances that could damage the stone surface.

When To Call a Sandstone Professional

While many sandstone step repairs can be DIY projects, some scenarios may require professional assistance.

• Structural damage to steps: Extensively damaged steps pose safety risks and need expert intervention
• Large-scale stone replacements: Extensive repairs might need specialized tools or experience
• Complex patterns or intricate layouts: Professionals can complete precise restoration to preserve design integrity
• Lack of proper tools or expertise: If you’re new to masonry, professional help can prevent costly mistakes

Consulting with a professional mason ensures that the job is done correctly, with reliable results.

Resources

Expert assistance by Metro Brick Repair. Materials supplied by The Mountain Stone Supply.

Tools