Drift: Roof Snow Load Calc

What it does

Drift answers the winter roof questions. The Roof Load Check and Roof Safe are free forever: fresh snow, packed snow, and ice in inches become an estimated load in pounds per square foot using FEMA's Snow Load Safety Guide equivalences — a foot of fresh snow is about 5 psf, packed snow triples that per inch, and one inch of ice weighs what a foot of fresh snow does — compared against FEMA's published 20–25 psf danger discussion. The safety floor never goes behind the paywall: FEMA's warning signs, the rake-from-the-ground rule, why flat roofs and barns fail first, and keeping vents clear.

And one thing Drift will never do: call your roof "safe." No app can see your rafters, your span, or your code year. Drift compares honest estimates to published figures and points at the rake or a structural engineer — that discipline is enforced by a unit test.

Drift Pro — one-time unlock

$6.99, once. Storm Planner: the forecast on top of what's already up there, and the call on raking before the storm. Drift Watch: wind banks snow against parapets and onto lower roofs at multiples of the field load. Ice Dam Check: the eave-strip weight of dam ice, plus the honest fix — heat cables treat the symptom, air-sealing treats the cause. No subscription, no ads, no account.

Privacy

Drift collects nothing. No analytics, no accounts, no cloud. Privacy policy · Support