How To Build Concrete Landscaping Stairs In Sections
Pouring an entire concrete stairway in a single day is a massive undertaking that often requires a dedicated crew, heavy equipment, and precise timing. For the ambitious do-it-yourselfer, tackling a landscape stairway project all at once can be overwhelming and physically exhausting. However, breaking the project down into smaller, more manageable sections provides a practical alternative without compromising the structural integrity of the final product.
While not the standard practice for professional crews, pouring landscape stairs in phases allows homeowners to mix and place concrete at their own pace. The secret to making this method successful lies in proper formwork modification and rigorous attention to steel reinforcement. When concrete is poured at different times, it creates a cold joint. To prevent the individual step sections from shifting, settling, or separating over time, they must be mechanically tied together using continuous rebar.
Modifying Formwork For Phased Pours
Standard stair forms are designed to hold the entire volume of concrete at once. When pouring in sections, you must create temporary bulkheads, or form boards, that cap off the end of your current pour. These boards must be strategically drilled or notched to allow your steel reinforcement to pass through. By letting the rebar protrude past the temporary form board, you provide a connection point for the next batch of concrete.
Once the first section has cured enough to hold its shape, the temporary bulkhead is removed, revealing the solid concrete face with the rebar dowels sticking out. This exposed steel is critical. As you build the forms for the adjacent section, the new concrete will encapsulate these protruding steel bars, bridging the cold joint and unifying the structure.
Structural Reinforcement And Placement
Steel reinforcement is the backbone of any segmented concrete structure. When creating landscape stairs on solid ground, the soil provides the primary support, but the concrete still requires tensile strength to resist cracking from ground movement and thermal expansion.
When overlapping rebar from one section to the next, ensure the steel runs continuously through the bulkheads. The overlapping bars must be tied securely together with steel wire. To maintain structural compliance, the steel must be suspended within the form cavity, ensuring it does not rest directly on the dirt. Standard building guidelines require specific concrete coverage around the steel to protect it from moisture and corrosion, which dictates exactly where your rebar should be positioned within the formwork.
Three Key Tips
Secure Rebar Lap Splices: When leaving rebar exposed to connect to the next section, ensure adequate overlap. A common industry standard is to lap the bars by at least forty times the diameter of the rebar. For example, half-inch rebar should overlap by at least twenty inches to create a strong mechanical bond.
Maintain Minimum Concrete Cover: To protect reinforcement from rusting, the International Residential Code requires a minimum of three inches of concrete cover for steel cast directly against the earth. If the concrete is poured into forms but remains exposed to the weather, maintain at least two inches of coverage.
Clean The Cold Joint: Before pouring the adjacent stair section, use a wire brush or pressure washer to remove any loose debris, dirt, or concrete slurry from the face of the previous pour. A clean, textured surface encourages better adhesion between the old and new concrete.
Bonus Questions And Answers
What Is The Ideal Tread And Riser Ratio For Outdoor Landscaping Stairs?
To complement your newly poured concrete sections, understanding proper layout geometry ensures your stairs are both comfortable and compliant with safety standards. For residential exterior stairs, the universally accepted guideline dictates a maximum riser height of seven and three-quarter inches and a minimum tread depth of ten inches. However, for outdoor landscape environments, extending the tread depth to twelve or fourteen inches with a shorter riser, such as six inches, creates a more gradual and natural transition across the sloping terrain. Consistent measurements across the entire flight are strictly required to prevent trip hazards.
How Do You Ensure Concrete Settles Properly Without Leaving Honeycomb Pockets?
Once your layout is designed and forms are in place, proper consolidation during the pour is vital for a smooth finish, especially when working around rebar. When concrete is poured, trapped air bubbles naturally collect against the form boards, leaving unsightly and structurally weak voids known as honeycombing. To prevent this, use a mechanical concrete vibrator or repeatedly tap the exterior of the wooden forms with a hammer as the concrete is placed. This vibration forces the aggregate to settle and drives the air bubbles to the surface, resulting in a dense, solid, and aesthetically pleasing stair face once the forms are stripped.
How Can You Prevent Spalling And Surface Damage On Exterior Concrete Over Time?
After your perfectly consolidated concrete has set, protecting your finished stairs from the elements becomes the final necessary step for long-term durability. Spalling, which is the flaking or chipping of the concrete surface, is typically caused by freeze-thaw cycles or excessive moisture penetration. To mitigate this, ensure the concrete is properly cured by keeping it damp for several days after the pour, which maximizes its strength. Once fully cured, usually after twenty-eight days, apply a high-quality penetrating siloxane concrete sealer. This treatment creates a hydrophobic barrier beneath the surface, preventing water absorption while allowing the concrete to breathe, significantly extending the lifespan of your landscaping stairs.
