What snow load actually does to a house
Snow load is a structural loss, not a roofing loss, and that distinction drives everything about how it should be documented. The damage isn’t the snow: it’s what the weight of the snow did to the frame underneath it. Rafters and trusses are sized for a design load; pile enough wet snow on top and the members deflect, the connections strain, and something gives. Often the roof surface still looks fine. The problem is in the framing you can only see from the attic.
Snow also doesn’t load a roof evenly, which is the part surface inspections miss. It drifts: deep against a dormer, in the valleys, and especially on a lower roof sitting in the wind shadow of a taller wall, where blown snow piles far past what fell. That concentrated drift load is where roofs fail, because it puts weight on framing that was never designed to carry it. The failure follows the drift, so the documentation has to as well.
New England gets the worst version of this. Heavy coastal snow is wet and dense; a midwinter rain-on-snow event can double the weight of the pack overnight; and the north-country and mountain zones carry some of the highest design snow loads in the country. By the time someone climbs up to look, the snow that caused the damage may already have melted or been cleared, which means the load is gone but the deflected rafter, the cracked truss plate, and the racked door frame remain. Those are the evidence, and they have to be measured and recorded before finishes get patched over them.
The structural indicators are specific and readable if you know to look: a ridge line that dips, a ceiling that bows, interior doors that suddenly bind in their frames, fresh cracks radiating from the corners of openings, and, in the attic, split rafters at the ridge, pulled fasteners, and cracked connector plates. None of that shows up in a scope written from the ground.
Why the frame is the file
A snow-load estimate that reflects only shingles and a little drywall has missed the loss. Atlas documents the load path and where the drift concentrated it, measures deflection and the structural indicators it left, records the framing and connection damage in the attic, and ties the interior finish cracking back to the movement above it. The result is a scope built around the structure that actually carried the load, with a 3D record of conditions before repair changes them.
