Retaining Wall Basics

At times a landscape has a section of ground that needs to be held back, particularly in the event of heavy rains.  The most practical solution is a retaining wall.  If the term makes you think of those ugly concrete or cinder block structures running along city sidewalks in some of the older urban neighborhoods, perhaps it’s time to take a look at this practical hardscape feature that not only serves a purpose but can provide some opportunities for unique landscape design features.  They can be tiered and filled with garden beds or rock gardens, or they can incorporate seating and small nooks for quiet contemplation.  The most important thing is that they need to be properly engineered by an experienced architectural landscape designer in order for them to function correctly as well as avoid being an eyesore.

Common Retaining Wall Materials

There are a number of materials commonly used for retaining walls, and what you choose will depend on you and your desired outcome.  Here are some popular stone or masonry materials:

Interlocking concrete blocks.   This is one of the most inexpensive choices, and also very flexible.  Since the blocks are fairly small, they work well to produce a wall that may be curved or irregular.  They are also easy to taper.  And since backfill can be poured into each block, they remain in place without the need for mortar.  Walls up to 20′ high can be constructed from these blocks.

Cinder block and brick.  Both of these materials must be installed with mortar, which also requires the use of some drainage system as well as a good footing.  Cinder block is relatively inexpensive and contemporary in appearance; brick is more formal.  Because of its smaller size, brick is more suitable to irregular or curved applications.

Stone.  Because of its weight, a stone wall does not require masonry to hold it in place; gravity should do the job.  Stone produces a very natural look, but its installation requires an experienced stone artisan.

Wood.  Of all the retaining wall materials used, wood is probably the warmest-looking.  But because it is not as strong as other choices, its use should be limited to low applications.  Choose pressure-treated redwood or fir for durability.

Poured concrete.  On its own, a poured concrete wall is not very attractive.  It has good strength, but for the best look it should be finished with tiles or decorative masonry.

The retaining wall is just the beginning.  It can be a focal point for your yard, and a spot for some unique garden beds, lighting, and other structures.  If  your yard has a slope that could use some creative landscape solution, consider a retaining wall.

Architectural Landscape Design provides retaining wall and other hardscape design and installation in the Minneapolis/St. Paul metro area.