Ice dam risk in East Bethel, MN
How often ice dams form in East Bethel
41.4 dam days a winter
Severe risk. On an ordinary house in East Bethel, conditions for an ice dam come on about 41.4 days in a normal winter, mostly in January and February.
East Bethel averages 64 inches of snow a year and about 113 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 East Bethel
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 16.8 | High |
| Typical, some insulation, not air-sealed | 41.4 | Severe |
| Older or poorly insulated, warm attic | 72.2 | Severe |
Sealing and insulating a typical attic takes out about 24.6 days a winter here. It drops the risk from severe to high. An older house with a warm attic should expect closer to 72.2 days.
What to do about ice dams in East Bethel
- 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.
- 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 444 kWh a winter in East Bethel, roughly $75 at 17 cents a kWh.
Which to spend on first: air sealing or heat cable.
East Bethel winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 13.8 | 28.3 | 12.8 |
| February | 10.7 | 28.0 | 10.7 |
| March | 11.2 | 21.1 | 5.5 |
| April | 4.1 | 2.2 | 0.2 |
| October | 0.9 | 0.3 | 0.0 |
| November | 12.7 | 9.5 | 2.6 |
| December | 10.5 | 23.9 | 9.6 |
East Bethel next to nearby towns
East Bethel ranks 11 of 103 Minnesota cities here for ice-dam days, behind Hermantown at 52.9 days.
- Ham Lake, MN 7 mi, 39.9 days
- Andover, MN 9 mi, 39.9 days
- Blaine, MN 13 mi, 39.9 days
- Anoka, MN 13 mi, 39.9 days
- Coon Rapids, MN 13 mi, 39.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Cedar, 3.9 miles from East Bethel. 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.