Rationale

The current standard recognizes Non metallic lath for vertical walls however some manufacturers also recommend use on horizontal applications (ceilings, soffits, etc). The proposed revision recognizes the current practice and installation of Non metallic plaster bases on horizontal/ceiling applications based on performance requirements in Specification C1788. Non metallic plaster base standards C1764/C1788 require minimum ultimate load of +/- 75 psf when subjected to E 330 transverse load tests. Per the Portland Cement Association, the weight of ¾” (C926) stucco is approximately 11 lbs/ sf. which demonstrates Non Metallic Plaster Base easily supports the weight of stucco in horizontal/ceiling applications with a significant factor of safety.