Fundamentals of a Successful Retaining Wall
There are many variables to be considered and factored into the design of a successful retaining wall. Check your local building codes regarding retaining wall height, and whether a structural engineer’s plan is required.
Most professional retaining wall companies either have an engineer on staff, or a relationship with one allowing you to obtain an estimate of cost for your project, including permitting, and an engineer’s plan and letter to be filed with your county courthouse; if required. In many areas the local building codes now state that plans must be filed on any retaining wall that exceeds four feet in height.
Here are items which are fundamental to the success of your retaining wall.
Compaction of the Soil
Thorough compaction of the soil (not to be confused with tamping) is necessary no matter what material you choose to build your retaining wall. After compaction, the soil is dense, less porous thereby minimizing hydrostatic pressure on the retaining wall. The stability of the soil behind any retaining wall is crucial to its long term success.
Use of Geogrid
Geogrid is a synthetic material used to fortify the compacted soil. As weight, or pressure is placed upon geogrid it holds the soil in place.
Internal Drainage System
One element with which every retaining wall system must contend is how rainwater will impact the soil behind it. The moisture will naturally cause the soil behind the wall to expand while applying hydrostatic pressure to your structure. An internal drainage system will ensure the moisture is diverted through the retaining wall thereby minimizing the pressure which could otherwise cause the failure of a retaining wall without proper drainage.
These are just a few of the construction components of a successful retaining wall system, but should give you ample information to ensure you ask the right questions to the retaining wall companies who come to estimate your project.
Landscape and Gardening Walls
Very small scale landscaping wall projects, designed strictly for aesthetics, are often constructed by landscaping companies or even the do it yourself landscape enthusiast.
However, it is important to be aware that most landscape or gardening block is much smaller in size and roughly just one third the weight of the segmental retaining wall block used by retaining wall companies. Therefore this type of landscaping block is not recommended for projects in which the gardening wall is more than 2 feet in height. That being said, small landscaping block, sometimes referred to as garden wall block, can be purchased at your local hardware store or garden shop.