Why does an ice dam cause damage inside the house?
Because the ice blocks the eave, meltwater has nowhere to run off, so it moves back up under the shingles. From there it reaches the sheathing, the insulation and eventually the ceiling below.
The shingles shed water well when they are flat and dry, but they are not a sealed membrane. Water pushed upward by a dam can work under the overlapping courses and reach the roof deck. Once it reaches the sheathing, it follows the rafters and the top plates.
That path explains why the ceiling stain may appear far from the roof edge. The water keeps travelling along framing and insulation until it finds a gap, a light fixture or a seam in the drywall.
Does the cold weather cause this, or the snow?
Both matter, but the cycle does more damage than either alone. Snow provides the meltwater, and repeated freezing and thawing at the eave is what builds the dam.
The National Weather Service's 1991 to 2020 average for the Kansas City observing site puts normal seasonal snowfall at about 18.2 inches. That is an approximate figure, and the snow that matters for a dam is the snow that sits on the roof for several days.
A single heavy storm followed by a sustained cold snap may do little. Several thaws and refreezes in a row are the pattern that produces a dam, which is why January through March is when most calls come in.
What should I do before the crew arrives?
Keep people and pets away from the stained ceiling, and move valuables out from under the wet area. Do not go onto the roof or chip at the ice yourself.
A ceiling that bulges or sags can give way without warning, so keep out from under it. If water is dripping onto a light fixture or an outlet, switch off the power at the panel before touching anything near it.
Take photos of the stain, the ceiling and any water on the floor before you move anything. Your insurer will want them, and the crew can add its own moisture readings and photos for the claim.
Is roof repair part of the job?
No. The crew does interior water damage, drying and cleanup, and it can do emergency tarping or board-up. Roof replacement and roof repair are for a roofer.
Roofing is a registered trade in Kansas. Every roofing contractor must hold a roofing contractor registration certificate from the Kansas Attorney General, in addition to any county licensing. Johnson County Contractor Licensing lists the roofing class, and its online contractor search shows whether a company is licensed and allowed to work.
Before a roofer starts, look the company up in that search. The search takes a few minutes and is worth doing before anyone cuts into a ceiling or pulls shingles.
What makes the price go up or down?
The size of the wet area, how far the water traveled, and what has to be removed and rebuilt are the main factors. The price is confirmed on site before any work begins.
A stain confined to one ceiling corner is a small job. Water that ran down a wall cavity, soaked insulation in the attic and reached a finished room below is a larger one, because more materials are removed and more drying is needed.
Access matters too. A ceiling with an attic hatch is easier than one reached through a finished second floor, and any mold already present turns the job into a containment job. The emergency stage is explained and approved before work starts, and repairs are quoted separately after drying, when the finished area can be seen.