WIND RESISTANCE DESIGN FOR LOOSE LAID BALLASTED AND VEGETATED ROOFING SYSTEMS

Protected Roof Membrane Assemblies (PRMA) have unique design requirements since they are loosely laid, held in place with stone ballast, pavers, or vegetative materials. The International Building Code contains prescriptive requirements to guide design and specification of such systems.

The standards reviewed in this program provide methods to design wind uplift resistance of ballasted and vegetated roofing systems. The standards are intended to be used as references for designing, specifying, and installing ballasted roofing systems, and are to be used in conjunction with the installation specifications and requirements from the manufacturers of the specific products in the system.

For roofs that exceed the boundaries of these standards (meaning designs that are not covered in this document) the “authority having jurisdiction” is the only source for approval. ASCE 7 gives guidance on how non-standard conditions should be evaluated. See other references, or, utilize professional wind engineering consultants, or, conduct wind tunnel studies in accordance with ASCE 7 for information to determine requirements for designs or systems not covered.