TechNotes for structural engineers

The National Research Council of Canada’s Institute for Research in Construction (NRC/IRC) has recently released an internet-based tool that simplifies the calculation of roof wind loads. These are a critical step in designing mechanically attached membrane roofs.

The Wind-RCI calculator is based on a six-step procedure developed by researchers at NRC-IRC with the Special Interest Group on Dynamic Evaluation of Roofing Systems (SIGDERS), but it greatly simplifies the calculations. It allows users to calculate wind loads for all Canadian cities by entering the building type, height, roof dimensions and type. It calculates roof cladding design loads and displays the wind load diagram for the field, perimeter and corner zones of the roof assembly. The bilingual tool is based on the National Building Code of Canada (NBC) 2005.