Retaining Wall Requirements
Spartanburg County requires a separate building permit for retaining walls four (4) feet in height or greater (measured from the bottom of the footing to the top of the wall) and any wall supporting a surcharge or impounding Class I, II or IIIA liquids whether site built or modular must be designed by a professional engineer who is currently registered to practice by the State of South Carolina. Upon approval of a retaining wall plan, a contractor, duly licensed for this work in South Carolina must obtain a permit to construct the wall. During construction, a “third party” South Carolina licensed “Special Inspector” shall inspect the work at prescribed stages and certify that the construction complies with the approved plans and Building Code certification is to be received by the Spartanburg County Building Codes Department prior to the issuance of a Certificate of Completion. Third party inspections are in addition to the normally required footing and formwork inspections prior to pouring concrete. For segmented walls, a footing inspection is required prior to laying wall segments to determine wall location.
Please provide the following with permit application:
1. Two (2) copies of the proposed plan and specifications including the site plan showing the location of the retaining wall specifying the elevations at the top of each wall and bottom of each footing.
2. Structural details for each wall and footing that include:
- Drainage methods for relief of hydrostatic pressure
- Concrete design strength
- Slope of finished grade
- Backfill materials
- Modular walls should show types, spacing and embedment length of all geogrid reinforcement
3. Soil parameters used in design including:
- Soil bearing pressure
- Active and passive equivalent lateral fluid pressure
- Internal angle of friction
- Surcharge load
- Soils density
4. Concrete design compressive strength at 28 days
5. Material specifications for all steel reinforcement
6. Minimum lap splice lengths for steel reinforcement
7. Specified thickness of all structural concrete
8. Calculations prepared and sealed by a duly registered South Carolina Professional Engineer demonstrating the structural adequacy of each proposed wall to resist the applicable design loads within the specified allowable soil bearing pressure and to maintain a minimum factor of 1.5 of safety against overturning and sliding
9. Name, address, contact information and SCLLR License number of Third Party Inspector including inspection frequency established by the engineer
Use of SCDOT standard wall designs does not relieve the Engineer of the responsibility to verify soil parameters; parameters must reflect field verified conditions at the time of plan submission.
Retaining walls designed for water retention as part of a storm water management plan are required to follow the requirements for commercial retaining walls.