Ice dam risk in Elk River, MN
How often ice dams form in Elk River
42.7 dam days a winter
Severe risk. On an ordinary house in Elk River, conditions for an ice dam come on about 42.7 days in a normal winter, mostly in January and February.
Elk River averages 36 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 Elk River
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 16.5 | High |
| Typical, some insulation, not air-sealed | 42.7 | Severe |
| Older or poorly insulated, warm attic | 75.5 | Severe |
Sealing and insulating a typical attic takes out about 26.2 days a winter here. It drops the risk from severe to high. An older house with a warm attic should expect closer to 75.5 days.
What to do about ice dams in Elk River
- 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 472 kWh a winter in Elk River, roughly $80 at 17 cents a kWh.
Which to spend on first: air sealing or heat cable.
Elk River winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 8.2 | 28.3 | 12.7 |
| February | 7.3 | 28.0 | 11.6 |
| March | 6.3 | 21.1 | 5.7 |
| April | 2.4 | 2.2 | 0.3 |
| October | 0.2 | 0.3 | 0.0 |
| November | 5.3 | 9.5 | 2.4 |
| December | 6.0 | 23.9 | 9.9 |
Elk River next to nearby towns
Elk River ranks 10 of 103 Minnesota cities here for ice-dam days, behind Hermantown at 52.9 days.
- Otsego, MN 5 mi, 36.5 days
- Ramsey, MN 7 mi, 40.1 days
- Big Lake, MN 9 mi, 36.5 days
- Rogers, MN 10 mi, 36.5 days
- Dayton, MN 11 mi, 40.1 days
Where these numbers come from
NOAA 1991–2020 climate normals from Elk Rvr, 2.1 miles from Elk River. 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.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.