IceDamCheck

Ice dam risk in Northlake, IL

Will your roof get ice dams in Northlake, IL?

13.3 dam days a winter

Moderate risk. On an ordinary house in Northlake, conditions for an ice dam come on about 13.3 days in a normal winter, mostly in January and February.

Northlake averages 38 inches of snow a year and about 44 days with snow on the ground. Most of it comes and goes within a few days. 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 Northlake

AtticDam daysRisk
Air-sealed and well insulated6.5Moderate
Typical, some insulation, not air-sealed13.3Moderate
Older or poorly insulated, warm attic21.7High

Sealing and insulating a typical attic takes out about 6.8 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 21.7 days.

What to do about ice dams in Northlake

  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.

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

Northlake winter, month by month

MonthSnow (in)Days on groundDam days
January11.316.15.8
February10.711.93.7
March5.54.60.8
April1.30.50.0
October0.20.00.0
November1.81.30.2
December7.69.22.7

Northlake next to nearby towns

Northlake ranks 116 of 225 Illinois cities here for ice-dam days, behind Arlington Heights at 21.5 days.

Where these numbers come from

NOAA 1991–2020 climate normals from Chicago Ohare International Airport, 3.5 miles from Northlake. 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.