Using Retaining Walls to Gain More Property
We live and work in the foothills of the Great Smoky Mountains. Anyone who has spent time in East Tennessee knows there are hills and valleys. Retaining walls are very versatile and can be used to raise an area that is sloping down or to cut into a slope to create more area. Because of those hills and valleys, sometimes having a flat area is hard to come by. With that in mind, I would like to tackle Segmental Retaining Walls.
We recently finished a project using a retaining wall to give a family more room for their vehicles. The family has camper as well as a new driver and needed more driveway. The solution we came up with was to construct the retaining wall 30 feet from the existing driveway to allow them a 30x25 parking pad. For this area we needed to build the wall to a height of 8 feet at the tallest corner. In our area, a retaining wall constructed over 4 feet tall is required to have an engineer draw up construction plans to take into account the weight that will be above the wall in the future.
One of the decisions we had to make early on was the future usage of the new area. The customer mentioned possibly constructing a detached garage. The engineering took this into account for the design and came up with an engineered plan that would allow the customer to build the future detached garage. Because a retaining wall is retaining a weight or mass, thought needs to go into what that weight will be and how the retaining wall will keep the mass in place.
What is a Segmental Retaining wall? It is a manufactured concrete block that is engineered and manufactured to be constructed to hold back a weight or mass. Holy smokes, this post could get a little technical, but stick with me. I will define some terms to clear up some possible confusion.
Block - The actual retaining wall block that is stacked to give us a finished look. We use a variety of manufactures who produce utility style block that do the job and look decent. We also use block material that are very nice and increase the beauty of your space.
Reinforced Zone - The area behind the block that acts as the load bearing zone. This is where gravel backfill and geogrid reinforcement are placed. This is where the retaining magic really happens. The combination of gravel and geogrid are the real strength of a retaining wall project.
Geo Grid - An engineered mat that is placed 16-24 inches apart during wall construction and through the reinforced zone.
Footer - Segmental Retaining Walls are constructed on a compacted, dense graded aggregate footer/footing. Rule of thumb is that for every 1-foot increment of wall height, 1 inch of wall block will be buried below undisturbed soil at bottom of wall.
Cap - Most wall blocks are constructed hollow to allow gravel to fill the void. A cap piece is installed at the very top of the wall to give a finished clean look.
At Paragon Hardscapes, we take retaining walls very seriously. I have seen several retaining wall projects that have failed due to poor construction practices. A retaining wall failure will be very expensive to repair as well as possible property damage or personal injury that can occur. Maybe we will do a retaining wall failure post in the future.
How can a Segmental Retaining Wall increase the space and value of your property?