IceDamCheck

Ice dam risk in Lockport, NY

Will your roof get ice dams in Lockport, NY?

21.4 dam days a winter

High risk. On an ordinary house in Lockport, conditions for an ice dam come on about 21.4 days in a normal winter, mostly in January and February.

Lockport averages 80 inches of snow a year and about 73 days with snow on the ground. Snow that lies that long is what turns a little attic heat into a ridge of ice at the eave. The conditions that make a dam need all three at once: snow, cold at the eave and heat above it.

What your attic does to that number in Lockport

AtticDam daysRisk
Air-sealed and well insulated11.3Moderate
Typical, some insulation, not air-sealed21.4High
Older or poorly insulated, warm attic34.0High

Sealing and insulating a typical attic takes out about 10.1 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 34.0 days.

What to do about ice dams in Lockport

  1. Air-seal the attic floor: the gaps around the hatch, light fixtures, plumbing stacks and the top plates of interior walls. This is the fix that removes the cause, and it usually costs less than a season of contractor ice removal.
  2. Rake the bottom three or four feet of roof after any storm that leaves more than about six inches, from the ground with a roof rake.
  3. At the next reroof, ask for ice-and-water membrane under the shingles from the eave to at least 24 inches inside the wall line. It does not stop a dam; it stops the leak when one forms.

Which to spend on first: air sealing or heat cable.

Lockport winter, month by month

MonthSnow (in)Days on groundDam days
January22.922.07.4
February16.120.46.9
March13.112.52.8
April2.71.00.1
October0.50.10.0
November6.03.10.4
December18.513.73.8

Lockport next to nearby towns

Lockport ranks 28 of 90 New York cities here for ice-dam days, behind Utica at 46.1 days.

Where these numbers come from

NOAA 1991–2020 climate normals from N Tonawanda, 11.4 miles from Lockport. A dam day is a day with snow on the roof and freezing at the eave while heat or sun melts the snow above it. This describes a normal winter, not this one.