IceDamCheck

Ice dam risk in Plover, WI

How often ice dams form in Plover

37.8 dam days a winter

Severe risk. On an ordinary house in Plover, conditions for an ice dam come on about 37.8 days in a normal winter, mostly in February and January.

Plover averages 49 inches of snow a year and about 102 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 Plover

AtticDam daysRisk
Air-sealed and well insulated15.1High
Typical, some insulation, not air-sealed37.8Severe
Older or poorly insulated, warm attic66.2Severe

Sealing and insulating a typical attic takes out about 22.7 days a winter here. It drops the risk from severe to high. An older house with a warm attic should expect closer to 66.2 days.

What to do about ice dams in Plover

  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.
  4. Heat cable is worth pricing here even on a sealed house, along the eave and in the gutters and downspouts it drains into.

Running 60 feet of 5 W/ft cable whenever snow lies below freezing would use about 409 kWh a winter in Plover, roughly $70 at 17 cents a kWh.

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

Plover winter, month by month

MonthSnow (in)Days on groundDam days
January11.627.112.0
February11.527.911.3
March6.918.55.0
April4.23.00.4
October0.30.20.0
November1.94.31.1
December12.320.78.0

Plover next to nearby towns

Plover ranks 9 of 98 Wisconsin cities here for ice-dam days, behind Wausau at 41.6 days.

Where these numbers come from

NOAA 1991–2020 climate normals from Stevens Pt, 4.1 miles from Plover. 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.