21 NCAC 28B .0508          WALLS

(a)  When installing retaining walls, the licensed contractor shall:

(1)           Adhere to all pertinent codes;

(2)           Adhere to all NC Department of Insurance requirements regarding the construction of retaining walls which are hereby incorporated by reference and can be found at www.ncosfm.gov/codes free of charge;

(3)           Adhere to manufacturer's or design professionals specifications;

(4)           Bury the first course of a retaining wall;

(5)           Not construct dry-laid stone walls of a height more than 3 feet above grade;

(6)           Include a subdrain system that is constructed and sized to release the subsurface water behind the wall and not allow hydrostatic pressure to build behind the wall;

(7)           Construct on a level, well-compacted base of granular material at least 6 inches deep;

(8)           Place backfill behind retaining walls in lifts no greater than 6 inches before compacted (each lift shall be well-compacted);

(9)           Prevent excessive runoff from passing over a retaining wall;

(10)         Construct vertically-set timber walls with above-ground heights equal to or less than the depth of timbers below grade;

(11)         Install deadmen every fourth course on 8 feet centers when constructing horizontally-set timber retaining walls with staggered joints;

(12)         Stagger the joints when constructing dry-laid stone walls. If successive vertical joints occur, the licensed contractor shall avoid running vertical joints more than two courses; and

(13)         Assure that segmental walls meet the manufacturer's specifications.

(b)  When installing retaining walls of dry-laid stone or concrete rubble, the licensed contractor shall:

(1)           Construct the wall no higher than 3 feet above grade; and

(2)           Stagger the joints when constructing a dry-laid stone wall.

(c)  When installing freestanding walls, the licensed contractor shall:

(1)           Install footings for masonry and cast-in-place concrete freestanding walls of reinforced concrete. The top of the footing shall be at least 1 foot below grade.

(2)           Reinforce freestanding walls as needed to prevent displacement from wind loads.

(3)           Ensure that moisture is prevented from entering a cavity wall during construction.

(4)           Ensure that segmental wall construction meets segmental wall manufacturer's specifications.

History Note:        Authority G.S. 89D-15(2); 89D-15(16);

Temporary Adoption Eff. January 1, 2016;

Eff. September 1, 2016;

Amended Eff. July 1, 2021.