Ice dam risk in Chippewa Falls, WI
Will your roof get ice dams in Chippewa Falls, WI?
36.1 dam days a winter
Severe risk. On an ordinary house in Chippewa Falls, conditions for an ice dam come on about 36.1 days in a normal winter, mostly in January and February.
Chippewa Falls averages 55 inches of snow a year and about 99 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 Chippewa Falls
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 14.7 | Moderate |
| Typical, some insulation, not air-sealed | 36.1 | Severe |
| Older or poorly insulated, warm attic | 62.8 | Severe |
Sealing and insulating a typical attic takes out about 21.4 days a winter here. It drops the risk from severe to moderate. An older house with a warm attic should expect closer to 62.8 days.
Preventing ice dams on a Chippewa Falls roof
- 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.
- 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.
- 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.
Chippewa Falls winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 13.5 | 26.8 | 11.6 |
| February | 11.2 | 25.8 | 10.2 |
| March | 9.6 | 17.6 | 4.6 |
| April | 4.3 | 3.1 | 0.4 |
| May | 0.4 | 0.1 | 0.0 |
| October | 0.7 | 0.2 | 0.0 |
| November | 4.7 | 5.2 | 1.3 |
| December | 11.0 | 20.6 | 7.9 |
Chippewa Falls next to nearby towns
Chippewa Falls ranks 11 of 98 Wisconsin cities here for ice-dam days, behind Wausau at 41.6 days.
- Eau Claire, WI 10 mi, 33.4 days
- Menomonie, WI 26 mi, 32.7 days
- New Richmond, WI 58 mi, 38.8 days
- River Falls, WI 61 mi, 38.8 days
- Winona, MN 63 mi, 30.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from Chippewa Valley Regional Airport, 6.7 miles from Chippewa Falls. 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.