June 15, 2017 –  Retaining walls are a popular feature for hilly residential lots. The Soil Science Society of America (SSSA) June 15 Soils Matter blog post explains what factors to consider—and when to call in the pros.

“Retaining walls are hard-working structures that fight a constant battle against gravity, so consider many variables when developing them,” says Christina Hebb, a soil scientist with Duraroot. Questions to consider include:

• What is the slope? If it’s greater than a 3:1, landowners should always consult an engineer.
• How much frost and freezing will your wall – and the soil it’s holding – be subject to?
• What is the drainage like? If water will flow heavily on the wall and soil, you may need to add drainage.
• What type of soil do you have? A soil with a heavy clay content will not drain well, but is also less prone to erosion. A sandy soil has the opposite characteristics.
• Are there any other structures near the proposed site? What influence will the wall have on the structures?
• Do you live in an area of where there are anticipated earthquakes? Will an earthquake engineer be needed to analyze the wall to make it more resistant to earthquakes?

“You may need a professional to help you to assess the soil in the area you plan the wall,” Hebb adds. “Also look at the climate and terrain – this will help you know if this is a weekend job for you, or whether you need professional help.”

To read the entire blog post, visit https://soilsmatter.wordpress.com/2017/06/15/how-do-retaining-walls-work/.

Follow SSSA on Facebook at https://www.facebook.com/SSSA.soils, Twitter at SSSA_Soils. SSSA has soils information on www.soils.org/discover-soils, for teachers at www.soils4teachers.org, and for students through 12^th grade, www.soils4kids.org.