In many areas of the country, retaining walls on residential property are built for reasons that are primarily aesthetic and are common when people want to create a tiered effect for their yard or when the slope of the property is, for one reason or another, undesirable. However, in an area with as many hills and streams as Pittsburgh, retaining walls can actually be built in residential areas for the same reasons they are built in industrial or commercial settings, which is to prevent erosion and to keep soil from going where it is not wanted. Since homes in the area might truly benefit by erecting a retaining wall, Pittsburgh residents should know what situations one works best in, and what options are available if they decide to build one.
Physical Benefits of Retaining Walls
Land that is flat and level to begin with probably has no need for a retaining wall. Though soil erosion can occur in flat places, wind, not water, is generally the culprit. In Pittsburgh where hills and streams are plentiful, a retaining wall can reduce the amount of soil that gets washed away during a rain storm, as well as make the slope of a property less of an issue.
Those who have a stream that actually flows through their property can benefit even more by building a retaining wall. At water's edge, the amount of soil that gets carried away during and after a heavy storm can be much greater than that caused by water simply flowing downhill. This is even more apparent when there are few or no plants or trees on the water's bank to hold the soil together. A retaining wall placed near where land meets water can greatly reduce soil erosion and keep dirt and debris from going into the water.
Pittsburgh Retaining Walls for Aesthetics
Just because there are structural reasons for building a retaining wall in the land of three rivers, that doesn't mean you can't take advantage of the aesthetic benefits of them, as well. Due to the slopes of many people's properties in Pittsburgh, a series of retaining walls made to create tiers can be a very effective landscaping method. It not only changes the look of the actual land, but it can also allow you to grow decorative plants more successfully by controlling the flow of rain water or water coming from sprinklers. Tiers can also make a good place for stairs in a walkway that might otherwise be just a steep path.
Types of Retaining Walls
A retaining wall can be made in a few different ways. It can be made of stone or brick and mortar, it can be made of poured concrete that is set in a mold, or it can be made in a "dry" stone method (where stones use friction and gravity instead of mortar to stay in place). In situations that require a significant amount of structural strength, poured concrete or mortared masonry is probably the best choice, as dry stone walls aren't structurally sound in this capacity when they get much more than 3 feet high. If you don't mind making several walls, you might consider making a few separate dry stone walls to hold back soil a few feet at a time.
Retaining Wall Prices in Pittsburgh
The cost of building a retaining wall in the Pittsburgh area ranges widely. Some are built for under $1,500, while others can be as high as $10,000. The average national price for building a retaining wall is around $5,000, and individual projects vary so much because of the length and height of the wall, as well as how it is constructed. Dry stone walls are the least expensive, followed by poured concrete. Masonry is the most expensive because it takes the most effort and the most time to build. If this is a project you're seriously considering, make sure to get estimates from a few different companies and for each building method. 
Jon Nunan is a freelance writer who draws on his experience in construction, ranging from landscaping to log home building, for his articles on home improvement.