Ice dams and icicles on a Liverpool, NY house: the eave decides the repair

An ice dam forms when snow melts higher on the roof and refreezes at the cold overhang. The water behind it has nowhere to go, so it backs up under the shingles and into the deck and the wall below.

The part of the fix that belongs to the roof is at the edge, where the code asks for a drip edge, and for an ice barrier where ice has formed along the eaves before.

In the county hazard plan nothing in Liverpool's annex ranks above winter weather, and its median house was built in 1938. A house that old may have no barrier at the edge, so ask what is under the shingles at yours before you decide how far the work should go.

The barrier is a pair of cemented underlayment layers or one self-adhering sheet, and it reaches 24 inches or more in from the wall line. Ask the roofer to write down the distance they plan for your house.

March is the worst month for this. Syracuse crosses freezing in both directions on more days in March than in January, and each crossing is a chance for meltwater to refreeze at the edge. A stain that shows only then is a clue about timing, and the roofer should hear it.

It may be that the field is sound and the eave is not. Ask the roofer to price the eave rebuild as its own line, and to price the full replacement beside it. Boards along the edge that are wet or spongy would belong in the eave price.

The Department of Energy traces the upstream cause to warm air reaching the roof deck, which is a separate job from the roofing. A new eave does not fix that, so ask the roofer what they see at the edge, and tell us the room and the month when you book.

Before you book, decide what you want to learn from the visit. You want to know where the water entered, what is under the shingles at the edge and whether the deck is dry. A roofer who can tell you those three things has earned the estimate.

Ask whether the old shingles will come off the lowest rows only or the whole slope. Ask whether any barrier already sits under them. Ask how the roofer handles boards at the edge that turn out stained or soft. A roofer who answers each one with a line on the estimate is giving you something you can compare.

Ask too about the drip edge. State code asks for one on the eaves of a shingle roof, and it is a small part that is easy to leave off an estimate. If it is missing from one quote and listed on the other, the quotes are not the same job.