Implementation of the 2015 International Residential Code will permit the use of ramps having a slope not greater than 1 unit vertical in 8 units horizontal in residential construction when the ramp does not serve the required egress door. Prior to 2015, section R311.8 of the IRC required to have a maximum slope of 1 unit vertical in 12 units horizontal, regardless of whether the ramp served the required egress door.
The 2015 IRC went into effect on July 1, 2016 in South Carolina. SC Code Schedule