A sloped or hilly backyard presents a unique landscaping challenge. Retaining walls are often necessary to create usable spaces and prevent erosion on steep slopes. With the right design, retaining walls can be both functional and beautiful additions to your outdoor living area. Here are 26 terrific retaining wall ideas to inspire your project in a sloped backyard.
What is a Retaining Wall?
A retaining wall is a structure designed to hold back or retain soil, rocks or other material behind it. It prevents downslope movement and provides support for abrupt changes in ground elevation. Retaining walls keep soil and debris in place so that landscaping and usable spaces can be created on the leveled area above the slope.
Retaining walls are typically constructed from materials like concrete, natural stone, bricks, blocks, gravel, wood and metal. The ideal material depends on factors like load requirements, durability needs, budget and aesthetics.
Benefits of Retaining Walls for Sloped Backyards
Installing properly designed retaining walls offers many benefits for hilly and sloping backyards:
- Creates usable flat zones for seating, play areas, fire pits, gardens, sheds, pools and other landscaping features that would otherwise be difficult on a slope.
- Prevents erosion and downhill washout of soil that can occur on steep slopes, especially during heavy rains.
- Provides support to stabilize grounds around foundation areas, patios, walkways and other structures placed on or near a slope.
- Can terrace or step a slope gradually, allowing for multiple landscaping layers.
- Aids drainage and controls water runoff on hillsides.
- Provides privacy when designed as a tall barrier.
- Enhances aesthetics with choices like decorative patterns, textures, colors.
- Increases property value by maximizing usable space.
- Long lasting when properly engineered and constructed from quality materials.
Design Considerations for Retaining Walls on Slopes
Proper design is crucial when installing retaining walls on hilly backyards. Here are key factors to consider:
- Gravity walls: Use large, heavy materials like natural stone or concrete blocks that rely on their weight to stay upright and stable.
- Geogrid walls: Geogrid is a soil reinforcement mesh that provides stability when built into retaining wall blocks.
- Anchored walls: Walls are secured with anchors, nails, or deadheads embedded in stable soil zones behind the wall.
- Drainage: Provisions for proper drainage, like gravel backfill, drainage pipes and weep holes, are critical to avoid buildup of pressure from water behind the wall.
- Batter: Walls are slightly set back or angled in towards the slope to improve stability.
- Height: Tall retaining walls require geogrid, anchoring, special engineering, permit requirements. Keep under 4 feet when possible.
- Soil type: Clay soils exert more pressure than sandy soils. Retaining walls on clay soil require more robust engineering.
- Surcharges: Nearby structures like pools, roads or driveways that add extra weight require special reinforcement.
Consulting with a qualified landscape architect or engineer is recommended to ensure your retaining walls are properly designed for site conditions.
26 Great Retaining Wall Ideas for Sloping Backyards
Here are 26 excellent options to inspire your retaining wall project on a sloping backyard:
1. Stacked Stone Retaining Wall
This natural stacked stone wall blends beautifully while doing its job stabilizing the slope. Irregular sizes and shapes create an organic texture. Use local stone for added geo-friendliness.
2. Textured Concrete Block Retaining Wall
Modern, modular concrete blocks are available in varied earthy hues and come textured to emulate stone. The blocks fit together for easy DIY installation. Perfect for contemporary settings.
3. Gravity Limestone Block Retaining Wall
These substantial blocks of quarried limestone have a clean-cut look. Their weight creates a gravity wall that withstands slope pressure. Excellent choice for shoulders of a hillside driveway.
4. Short Railroad Tie Retaining Wall
For quick definition between upper and lower levels, inexpensive railroad ties work wonderfully. Their short height suits gradual slopes. Set into dirt or gravel and go rustic.
5. Long Railroad Tie Retaining Wall
Extend the rustic vibe with a taller railroad tie option that better defines tiered sections. The long edges stacked together produce a vertical log look. Add sod above for an organic-meets-industrial style.
6. Minimalist Concrete Retaining Wall
Poured concrete makes a strong, sleek statement when formed into a simple retaining wall. Use the reclaimed space above for a patio, fire pit or other gathering area. For added interest, end the wall with a curved or angled side.
7. Stone-Patterned Concrete Block Retaining Wall
This precisely patterned concrete block replicates the look of natural stone. The blocks fit tightly together and the textured front imitates rock textures. Use to create intricate custom designs.
8. Multi-Height Concrete Retaining Wall
Tiering your concrete retaining wall creates pockets of usable space. Define planters, pathways, pools and other landscaping features. Mix solid and perforated blocks for variety and drainage.
9. Rustic Wood Beam Retaining Wall
Give your retaining wall a woodsy personality with a design made from log posts and wood beams. Perfect for enclosing a play area or fire pit seating. Add pea gravel or mulch on top for low maintenance.
10. Bold Boulder Retaining Wall
For an ultra dramatic look, use massive boulders stacked irregularly to create your retaining wall. A heavy-duty choice that makes a spectacular statement anchoring your sloped yard.
11. Stepped Flagstone Retaining Wall
Lovely rustic flagstones arranged in an offset pattern gracefully terrace the slope. Use available flat stones or cut quarried pieces to custom sizes. Great for controlling runoff.
12. Angled Flagstone Retaining Wall
The diagonal angle of this flagstone wall adds visual interest to the functional structure. Elongated stones running perpendicular to the slope line create textural drama. Perfect for defining garden beds.
13. Low Dry Stone Retaining Wall
A casually stacked low wall with no mortar lets the varied shapes and hues of the stone shine. Use rounded river rock for a soothing organic feel. Increase height gradually if more retention is needed.
14. Mortared Natural Stone Retaining Wall
For a tidier, more formal look, mortar can be used to set irregularly sized natural stones in straight courses. Choose a complementary color mortar to fit the stone. Great for creating planting beds.
15. Random Width Ledgestone Retaining Wall
Ledgestone features elongated flat pieces that give the look of natural cliff ledges. The uneven widths and random lengths laid in layers create a homey, rustic style perfect for cottage gardens.
16. Block and Gravel Retaining Wall
Permeable, gravel-filled blocks provide both stability and drainage for wet hillsides. The blocks stay put while allowing water to seep through. Use alongside walkways and French drains.
17. Gabion Retaining Wall
Gabion baskets filled with stone create unique, porous retaining walls. The cubed wire cages can be stacked in various patterns. They also work well for rustic staircases on a slope.
18. Architectural CMU Retaining Wall
Concrete masonry units like these with split-face detailing have a dimensional, contemporary look. Use for clean geometric lines in your outdoor spaces. Include drainage and high strength mortar.
19. Stacked Ledge Stone Retaining Wall
The linear edges of ledge stones create tidy, textured layers when stacked. Their blocky shapes allow for smoother lines than natural round stones. Great for contemporary or classic spaces.
20. Honed Granite Block Retaining Wall
Substantial granite block comes honed for a lightly polished finish. The luxurious stone exudes elegance wherever used. Random sizes laid in rows create interest with peaks and valleys.
21. Mortared Rubble Stone Retaining Wall
For an ancient, old-world look, use small irregular field stones mortared together. Leave gaps for character and plants. Use locally if available or source natural tumbled stones. Great for English cottage gardens.
22. Poured Concrete and Wood Retaining Wall
Join the strength of poured concrete uprights with the warmth of wood lengths on this contemporary retaining wall. Perfect for defining patios, walkways and other living spaces abutting the slope.
23. Stacked Stone Planters Retaining Wall
Use stone, concrete or cinder blocks to build garden planters right into your retaining wall. Plant cascading flowers, ferns or grasses above to soften the structure. Add a built-in water fountain for soothing sound.
24. Tiered Block Retaining Wall With Stairs
Break up a long slope transition by terracing retaining walls from stacked blocks. Leave spaces to tuck in steps made from the same block material or natural stone slabs. Adds handy access between levels.
25. Curved Stone Retaining Walls
Gently winding stone walls add a graceful, organic element as they terrace your yard. Use the reclaimed areas for curved walkways, fire pits or unique plant beds tucked in the curves.
26. Corner Block Retaining Wall
Define and anchor spaces while controlling erosion with block corner sections that turn the perfect 90 degrees. Continue straight sections from the corners or use corners alone to outline garden beds.
Building Your Retaining Wall in a Sloped Backyard
With proper planning and preparation, building a beautiful retaining wall in your hilly backyard is fully achievable:
- Study the slope area and how it naturally drains. Plan where to place the wall(s) and how to direct drainage.
- Remove all vegetation, organic material and unsuitable fill from the build zone. Level and compact soil to form a solid base.
- Stake out the wall layout and dig a trench to hold the first course below ground for stability.
- Plan for drainage elements like gravel, piping and weep holes. Backfill with gravel for max strength and water flow.
- Follow all manufacturer instructions for construction, like using recommended mortar, pins, geosynthetic reinforcement, etc.
- Stack courses carefully in the planned pattern, checking level and alignment often. Allow proper bonding time between courses.
- Taper and cap the wall for a finished look. Backfill behind and compact in layers as you go up. Slope soil away from the wall.
- Allow 30 days or more for drainage and curing before finishing landscaping around the wall.
- Maintain the wall by preventing erosion around it, sealing cracks, replenishing settled soil, cleaning drainage, inspecting for damage.
Retaining walls require patience and diligence to build, but are extremely worthwhile for yard enjoyment and property value. With attention to design factors and proper construction, you can have beautiful, functional walls that stand the test of time.
Frequently Asked Questions About Retaining Walls for Sloping Backyards
What is the best material for retaining walls on a slope?
Concrete, natural stone, and concrete block are top choices. Consider weight, durability, cost, and aesthetics for your yard. Proper drainage design is most critical.
How tall can you build a retaining wall without a permit?
Retaining walls over 4 feet tall may require an engineering design and permit. Keep below 4 feet when possible or consult local permit regulations for requirements.
Should the back of retaining walls be straight or sloped?
Sloping the backfill is better for drainage. Angle the wall in slightly or taper it back toward the slope about 1 inch per foot of height.
How far back should a retaining wall be from a slope?
Ideally, the base of the wall should be at least half as far back as the total height of the finished wall. More space is better to allow for proper drainage.
What can you put on top of a retaining wall?
On proper retaining walls, you can add standard landscaping elements like plants, paths, fences, benches, and lighting fixtures. Avoid adding extra weight like buildings, pools or vehicles.
How do you disguise the top of a retaining wall?
Using wall caps wider than the top course helps hide the wall edge. Planting trailing greenery to drape over the sides also helps conceal the top and hide where the wall meets the slope visually.
How much weight can a retaining wall hold?
This depends on the wall design, materials and proper drainage components. Typically, a minimum 12-inch deep gravel backfill will handle standard landscaping features. Consult an engineer for heavy structures or additional weight.
Enhance Your Sloped Yard with Beautiful Retaining Walls
With a well-designed retaining wall suited to your site and constructed properly, you can create an outdoor oasis with terraces, planters, stairs, patios and other livable spaces crafted right into the slope. Your landscaping options are boundless.
Sloped backyards offer fantastic potential, especially when thoughtfully sculpted with features like the gorgeous retaining walls we’ve covered here. Browse this collection of inspiring ideas, weigh the benefits, and start planning the perfect retaining wall project to maximize the enjoyment of your hilly backyard.