What an ice dam actually does to a house
An ice dam is a heat problem wearing a roof problem’s clothes. Warm air escaping the living space into the attic melts the snow on the upper roof. That meltwater runs down the sheathing to the eave (which hangs out over unheated space and stays below freezing), and there it refreezes. Do that for a few cold days and a ridge of ice builds at the eave. Now the next round of meltwater has nowhere to go but up and back, under the shingle courses, until it finds the edge of the ice-and-water membrane and gets into the sheathing behind it.
From there it follows the structure. It wets the roof deck, runs down the top plate of the exterior wall, and shows up as a brown ring on the ceiling near the outside wall, which is where most scopes stop. But the water that reached the top plate keeps going into the wall cavity below, behind the insulation, wetting studs and the back of the finish on the floor beneath. Crawl the attic and open that eave, and the wet line runs a lot further than the ceiling stain suggested.
Frozen pipes are the same story from a different pipe. A supply line run through an uninsulated exterior wall or an unconditioned bay sits in freezing air, the water inside expands, and the pipe splits. It often doesn’t leak until it thaws (frequently while the house is empty and the heat is set low), so it can release water for hours or days before anyone knows. The wet area is never just the fixture; it’s every cavity and floor the water reached while it ran.
Both losses share a root cause worth documenting: not enough insulation, not enough air sealing, a pipe in the wrong assembly. That cause is why it happened, and why it will happen again if left unaddressed. It belongs in the record as a condition, documented, not editorialized.
Why these losses have to be scoped in the attic and the wall
You cannot scope a winter loss from the ceiling stain. Atlas documents the meltwater path from the eave down, opens and maps the wall cavity below, locates the burst point and the freeze exposure that caused it, and records the attic insulation and ventilation behind the whole event. Moisture mapping and thermal imaging trace the water the finishes are hiding, so the estimate covers the roof, the assembly, and the drying: the actual size of a loss that started at the ridge.
