Proposed Allowable Patio Cover Column Downward and Uplift Loads for Residential Slabs-on-Grade

The current International Residential Code provides an allowable patio cover column load of 3.34 kN (750 lb) for a slab-on-grade foundation with a minimum 89 mm (3.5 in.) thickness. To provide for more design flexibility and reduce the need for costly engineering analysis, this article provides allowable column loads for varying slab-on-grade thicknesses, column locations, and concrete compressive strengths. The allowable downward loads determined herein exceed the current code-allowable load by a considerable amount in all but one case. Additionally, allowable uplift loads are determined, the provision of which is not addressed by the current code. It is intended that these updates be incorporated into the relevant building code.