Ice dam risk in Burlington, WI
Ice dams in Burlington, WI: how often
20.2 dam days a winter
High risk. On an ordinary house in Burlington, conditions for an ice dam come on about 20.2 days in a normal winter, mostly in January and February.
Burlington averages 38 inches of snow a year and about 57 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 Burlington
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 8.8 | Moderate |
| Typical, some insulation, not air-sealed | 20.2 | High |
| Older or poorly insulated, warm attic | 34.3 | High |
Sealing and insulating a typical attic takes out about 11.3 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 34.3 days.
Preventing ice dams on a Burlington 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.
Burlington winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 12.1 | 19.6 | 7.9 |
| February | 9.7 | 17.0 | 6.2 |
| March | 4.9 | 6.5 | 1.6 |
| April | 1.1 | 0.6 | 0.1 |
| November | 2.2 | 1.7 | 0.3 |
| December | 7.7 | 11.6 | 4.0 |
Burlington next to nearby towns
Burlington ranks 75 of 98 Wisconsin cities here for ice-dam days, behind Wausau at 41.6 days.
- Salem Lakes, WI 12 mi, 20.1 days
- Elkhorn, WI 13 mi, 19.2 days
- Muskego, WI 15 mi, 21.4 days
- Antioch, IL 17 mi, 20.1 days
- Fox Lake, IL 18 mi, 20.1 days
Where these numbers come from
NOAA 1991–2020 climate normals from Burlington Wwtp, 1.9 miles from Burlington. 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.