Retaining walls are usually constructed on sloping parcels of land that are presently eroding or in areas that will be cut (excavated) or filled-in in order to create more usable space. Retaining walls are customarily built from railroad ties, brick, block, stone or concrete. Railroad tie retaining walls usually are the most popular due to lower construction costs.
Existing rainfall drainage patterns are a major concern when planning to construct a retaining wall, since those patterns may be permanently altered by the structure(s) and the accompanying earthwork. Run-off that originates on your property or flows through your lot from adjacent properties must be adequately conveyed to a proper outfall to prevent any damage or nuisance to your neighbors. Additionally, groundwater movement must be addressed with the installation of weep holes and/or drain tile behind the wall.
To construct a retaining wall or series of walls that will have a total height of greater than two feet, a Building Permit must be obtained, and site plans showing existing and proposed construction location(s), including well and/or septic, must be submitted. Structural plans are also required. Retaining walls have the same set-back requirements as fences according to lot zoning.
If your home is located in a subdivision with a Homeowner’s Association (HOA), a separate approval from the HOA may be necessary. Unless erected by the homeowner, all home improvement projects require that a contractor licensed with the Maryland Home Improvement Commission is used.
For applicable forms, visit Forms and Checklists.