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 order to create more usable space. Retaining walls are customarily built from railroad ties, brick, block, stone or concrete. Railroad tie retaining walls are the most popular due to the 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, you must apply for a building permit and submit site plans showing existing and proposed construction location(s), including well and/or septic. Structural plans must also be submitted. Retaining walls have the same set-back requirements as fences according to lot zoning.
If you are 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 a contractor who is licensed with the Maryland Home Improvement Commission.
For applicable forms visit Forms and Checklists.