When you are looking to get more level space on your property, chances are you’re going to need to install a retaining wall. The Material choices are pretty simple. There are only three options for retaining walls: wood, block, or stone. Which option is best? There are pros and cons to each of them.
Wood Retaining Walls
Wood retaining walls were popular for about 100 years. With the advent of the automobile and highway system, creosote-dipped railroad ties were a readily available material for retaining walls. They would last for 40 years or more, and the weight of them was suitable for soil retention. In the mid 1970s, creosote railroad ties were replaced with 6×6 or 8×8 pressure-treated timbers.
Pros: Fast installation, affordable wall product, only basic construction skills needed
Cons: Only rated for 25 years in the ground, environmental concerns as they are treated with arsenic
Landscape block became the material of choice to replace landscape timbers in the early 1990s. The first concrete retaining wall block was very uniform and “blocky” looking. Since then, landscape block manufacturers have introduced many colors, patterns and styles to make them look more like natural stone.
Pros: Long lasting, easy installation after leveling, availability and variety of product
Cons: Higher cost than wood walls, may require engineering for retaining walls above 4 feet
Stone Retaining Walls
Natural stone has proven itself for thousands of years to be useful in retaining wall construction and erosion control. Its beauty and durability will even outlast concrete landscape block. In New Hampshire, stone retaining walls have always been popular due to the availability of natural stone.
Pros: Naturally beautiful and unique, adaptable for any home style, readily available material
Cons: High cost due to labor and material waste; best performed by a highly skilled installer
There are environmental factors to consider that determines the success or failure of a retaining wall over 4 feet high.
Building a retaining wall over 4 feet without considering soil structure, angle of slope behind the wall, drainage, and dead load weight on top – such as a parking area – can lead to disaster, property damage, personal injury or death.
At this point, the wall material itself is simply a veneer. It’s what’s built behind the wall that matters. Engineered retaining walls are designed with soil stabilization fabric at specific elevations to break up the “slip plane” pressure on the wall and drainage systems that channel stormwater down to the base and away from the wall.
If you are considering leveling your property by installing a retaining wall, but are unsure about tackling the project yourself, give the landscape office at Groundhog Landscaping a call. While we will not build a retaining wall out of wood, we can design and build a beautiful, functional wall out of block or stone for you that will stand the test of time.