§ 260-87.3
Retaining walls
[Added 9-12-2005 by Ch. No. 1551; amended 9-21-2020 by Ch. No. 1995; 10-26-2020 by Ch. No. 1997]
- A. Any retaining wall greater than six feet in vertical height, measured from grade at the bottom of the wall to the top of the wall, shall require a building permit. An application for a building permit under this section shall be reviewed and approved by the Zoning Officer prior to the permit being issued.
- B. A plot plan showing the property and the location of the proposed wall on the property, together with the location of driveways, sidewalks, patios, decks, pools and other structures and/or paving relative to the proposed wall, together with existing and proposed topography at two-foot intervals, shall accompany the permit application.
- C. Retaining walls shall be designed to ensure stability against overturning, sliding, excessive foundation pressure and water uplift. Retaining walls shall be designed for a minimum safety factor of 1.5 lateral sliding and overturning (Reference: Rhode Island Building Code: Retaining Walls).
- D. Retaining walls in excess of six feet shall be designed for all loads specified in the applicable building code and in keeping with nationally recognized standards. Such designs shall be based on sound engineering and geotechnical principles. A site plan and wall design signed, stamped and dated by a professional engineer licensed to practice in the State of Rhode Island shall also accompany the application.
- E. Where multiple walls are situated in a terrace-like pattern, they shall be considered one wall for purposes of determining the height of wall if the horizontal separation between adjacent walls is less than or equal to the combined height of the walls multiplied by a factor of 0.75.
- F. Adequate protection to prevent an individual's accidental fall over the retaining wall shall be erected and maintained in conjunction with the retaining wall thereafter.