Those are indeed serious ice dams pictured on page 63 of the March issue (“An Ice Dam Analyzed”). There are problems with that roof, but also problems with the article.
Look at the melt/no melt graphs. Melting will occur only when heat gain at the roof surface/snow interface exceeds heat lost to the environment; that’s a law. Given the conditions described — conduction loss only, R-30 roof insulation, an inside temperature of 74°F (!), and an interface temperature of 32°F — steady-state heat gain will be 1.4...
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