About

SNOW LOAD CALCULATOR

Short description: Roof snow load the NBCC way - balanced load plus drift at steps and parapets, with diagrams and a shareable PDF report.

Full description / Help: Work out the specified snow load on a roof with the National Building Code of Canada formula S = Is[Ss(Cb x Cw x Cs x Ca) + Sr]. Pick Ottawa, Montreal or Toronto to fill Ss and Sr (both stay editable), or choose Custom and type any city's values. Enter the roof slope, tick the box if the roof is unobstructed slippery metal, pick the importance category, and get the load in kPa and psf with every step shown.

The drift section handles snow piling against a roof step or a parapet: Case I (wind off the upper roof), Case II (wind off the lower roof), and parapet drift. It gives the peak accumulation Ca0, the drift length xd, and the load at the wall, at mid-drift, and beyond the drift.

Diagrams drawn in the app show each case as you pick it, and the Theme chooser switches the look - Winter Navy, Roofing Bold, or Concrete & Steel. The PDF REPORT button builds a two-page report with your inputs, results and the diagrams, opens a pinch-zoom preview, and saves to Downloads or shares to any app.

A field estimate, not an engineered design.