Introduction
Retaining walls are essential in protecting your property from soil erosion, flooding, and other forms of land damage. The wall not only helps to maintain the structural integrity of your property but also adds a decorative touch to your outdoor space. However, building a retaining wall may seem like a daunting task, and the process can be complicated if not done correctly. By following our detailed step-by-step guide, you will be able to build a sturdy and long-lasting retaining wall with ease.
Step-by-Step Guide
Planning and Design
The first step in building a retaining wall is to plan and design the wall’s layout. An essential factor to consider when designing the wall is the height, length, and angle of the slope you are trying to retain. The wall’s height and the angle of the slope will determine the type of retaining wall you will need to build. The design should be compliant with local codes and regulations. Before digging, contact your local building department to obtain necessary permits.
Site Preparation
Once you have a design, prepare the site by digging a trench that is at least four to six inches deep and twice the width of the wall’s base. The depth ensures the wall can endure the sheer force generated from the retained soil’s weight. Take into consideration the width of the base of the wall and the trench backfill, which should be at least six inches.
Excavation
Excavate the trench and the slope accordingly. Ensure the slope is smooth and leveled using a rake. If you encounter any rocks, boulders, or trees, remove them from the trench and slope to create a level surface. Ensure you retain any soil that will be used as backfill.
Laying the Foundation
The foundation of a retaining wall is critical in ensuring the wall’s structural integrity. A robust foundation should provide sufficient support to the wall. The foundation should be made of crushed stone or gravel. Add a four to six inch layer of crushed stones at the bottom of the trench. Spread and compact the crushed stone layer evenly throughout the trench using a hand tamper.
Building the Wall
Start by installing the base layer of your retaining wall. Use interlocking concrete blocks for a simple and efficient installation. Be sure to choose high-quality and robust blocks for long-lasting durability. Install the first row of blocks according to the proper placement. Ensure the blocks are level and perpendicular to the slope you are trying to retain. Use a string line to guide you in placing the blocks straight and level.
Backfilling
Between each row of the retaining wall, add three to four inches of gravel or crushed stone behind the wall to improve drainage. Ensure each layer is level and securely held together by the block connectors. Insert a geogrid behind the wall’s first three layers to help stabilize the structure. Once the wall installation is complete, backfill the remaining trench area using the retained soil.
Finishing Touches
After you backfill, use topsoil to level behind the retaining wall and around the base of the wall. Hydroseed or sod as necessary to finish the project. Use landscape fabric to cover the exposed soil behind the retaining wall, add plants, and rocks to enhance your landscape.
Materials and Tools
Materials
- Interlocking concrete blocks
- Crushed stones
- Geogrid
- Gravel
- Topsoil
- Landscape fabric
Tools
- Shovel
- Wheelbarrow
- Level
- Hand tamper
- String line
Techniques and Tips
Proper Drainage Techniques
Ensure that proper drainage techniques are in place, such as installing a perforated drainage pipe behind the wall’s base. This helps release water that may accumulate behind the wall, reducing hydrostatic pressure damage that could cause the wall to bulge, lean, or crack.
Site Preparation Considerations
Ensure the slope behind the retaining wall is cleared of debris and rocks. Grade the slope away from the wall at a six-inch drop per foot of distance and make sure the ground remains stabilized. Consider adding a drainage swale next to the retaining wall to prevent water from accumulating behind the wall, which can cause the structure to fail.
Construction Details to Ensure Efficiency and Durability
Interlocking blocks come in various sizes, shapes, and colors. Choosing the right block style will save costs, resources, and time. The blocks should be spaced accurately, and for a more aesthetic look, use different color blocks alternatively. Interlocking blocks provide structural stability. They are versatile and can act as garden steps or raised flower beds.
Tips to Avoid Common Mistakes
Avoid stacking blocks more than three feet without a geogrid tieback grid. The wall’s radius determines the geogrid’s location behind the first three block layers. Be sure to choose the right geogrid for your specific needs and ensure it is installed correctly to prevent the wall from failing.
Cost and Budgeting
Factors Affecting the Cost of Building a Retaining Wall
Various factors will affect the cost of building a retaining wall, such as the wall’s height, location, soil conditions, and the materials used. The timeline for completing the project and the contractor’s experience will also affect the cost of the retaining wall project.
Tips on How to Budget and Plan for the Project
The best way to budget and plan for the project is by determining the retaining wall’s size, the materials needed, the project location, and hiring professional contractors. By including these factors in the budget, you will help to control the project’s cost and ensure your wall is built within budget.
Recommendations for Cost-Saving Measures
Consider using recycled and repurposed materials to reduce the project’s overall cost. Speak to your local home improvement store for any leftover materials that may be appropriate for the project.
Maintenance and Safety
Importance of Maintaining a Retaining Wall
Maintaining the retaining wall after installation is crucial in ensuring the wall continues to provide the necessary function. Regular inspections help to identify drainage issues or deterioration that could compromise the wall’s integrity.
Steps to Take to Preserve the Integrity of the Wall
Avoid digging around the wall to prevent destabilization. Regularly check the drainage pipes to ensure they are working correctly to avoid hydrostatic pressure buildup. Remove any vegetation or tree roots that are growing near the retaining wall since it could affect the wall’s stability and compromise its structure.
Safety Considerations
Building a retaining wall project is a risky activity that requires strict adherence to safety protocols, including wearing protective gear such as gloves, hard hats, and safety shoes. Ensure the worksite is free from tripping hazards and that you have someone to help in case of an emergency.
Conclusion
Building a retaining wall project is a worthwhile pursuit that adds a strong sense of safety, beauty, and functionality to your outdoor space. It is essential to plan and design your project to achieve a stable and long-lasting structure. Follow the tips and techniques we have outlined, and you will be able to create an attractive and durable retaining wall that will make you proud.