The cheapest type of retaining wall is poured concrete. Prices start at $4.30 per square foot for poured concrete, $5.65 for interlocking concrete block, $6.15 for pressure-treated pine, and about $11 for stone.
How high can you build an Allan Block wall?
How High/Tall Can I Build a Retaining Wall with Allan Block? Unreinforced Allan Block walls or gravity walls, can be built up to 5 ft high (1.5 m) in sandy soils and up to 3.5 (1.0 m) ft in clay soils. Follow the Allan Block Installation Guide for easy installation instructions.
What size block do I need for a retaining wall?
For heavy-duty walls up to 30 ft. tall, go with full-size blocks. They’re 16 to 18 in. long x 6 to 8 in.
Does a 2 foot retaining wall need drainage?
These walls need a drainage system regardless of the wall height. If there are poor draining soils such as clay behind the wall, there needs to be drainage incorporated the wall system. Clay when wet is very weak, so it is essential to provide a way for water to escape from behind the wall.
What is the easiest retaining wall to build?
What is the easiest retaining wall to build? Short walls under three feet high and constructed of concrete blocks or masonry blocks are the easiest type of wall for DIYers to build. They are ideal landscape solutions for a front yard or raised flower bed.
Do you fill holes in retaining wall blocks?
Depending on your block design, there may be hollow cores in the blocks. If so, fill those cores with additional gravel to increase strength and stability.
Should retaining wall blocks be filled?
Stacking retaining wall blocks is easy. However, keeping them stacked for years is difficult. That’s why your DIY retaining wall must have a solid gravel base and firm backfill to ensure it’s stability.
Can you build a retaining wall with cinder blocks?
A cinder block retaining wall is only as straight and solid as the base it’s built on. For a 4-ft. tall wall, excavate a trench deep enough to accommodate 4 to 6 in.
How long do block retaining walls last?
If you’ve invested in durable materials and properly waterproofed the structure, a retaining wall can last 20 years or more. Timber can last for 40 years, and there’s no limit on how long cinder blocks or concrete walls can last when they’re built well.
How do you size a retaining wall?
Multiply the length and adjusted height measurement to determine the square footage of the retaining wall. Multiply the square footage number by 144 to find the size of the wall in square inches.
How do you build a retaining wall on a sloped yard?
Steps to Follow When Building a Retaining Wall on a Slope
Step #1: Get the Trench Compact and Level. Step #2: Install the Wall Rock. Step #3: Excavate the Second Level. Step #4: Place the Base Course of Blocks. Step #5: Compact the Wall Rock Behind the Blocks. Step #6: Fill in the Step Up Areas.
What are the best blocks to use for a retaining wall?
Concrete blocks are ideal for building walls to hold back the soil after you dig into a slope for a pathway, patio, or another landscaping project.
How deep should a base be for a retaining wall?
The general rule of thumb is to bury about one-eighth of the height of the wall. For example, if your wall will be three feet (36 inches) tall, the first course of blocks should start five inches below soil level. The gravel base should start three inches below this.
Can you backfill a retaining wall with dirt?
Second, a retaining wall must have properly compacted backfill. Backfill refers to the dirt behind the wall. In order to provide proper drainage, at least 12 inches of granular backfill (gravel or a similar aggregate) should be installed directly behind the wall.
How thick should a retaining wall be?
Base thickness = 1/8 of the height of the wall but not less than 12 inches. Stem thickness = 6 inches + ¼ inch for each foot of wall height.
