Ice dam risk in Rutland, VT
Ice dams in Rutland, VT: how often
28.5 dam days a winter
High risk. On an ordinary house in Rutland, conditions for an ice dam come on about 28.5 days in a normal winter, mostly in January and February.
Rutland averages 75 inches of snow a year and about 88 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 Rutland
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 15.0 | High |
| Typical, some insulation, not air-sealed | 28.5 | High |
| Older or poorly insulated, warm attic | 45.3 | Severe |
Sealing and insulating a typical attic takes out about 13.4 days a winter here. It does not move the risk band, but it shortens every dam. An older house with a warm attic should expect closer to 45.3 days.
What to do about ice dams in Rutland
- 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 242 kWh a winter in Rutland, roughly $41 at 17 cents a kWh.
Which to spend on first: air sealing or heat cable.
Rutland winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 18.3 | 25.0 | 9.4 |
| February | 16.0 | 22.2 | 7.8 |
| March | 13.8 | 17.2 | 4.6 |
| April | 3.2 | 2.4 | 0.3 |
| October | 0.3 | 0.1 | 0.0 |
| November | 4.7 | 3.8 | 0.7 |
| December | 18.3 | 17.7 | 5.6 |
Rutland next to nearby towns
Rutland ranks 4 of 4 Vermont cities here for ice-dam days, behind Essex Junction at 33.5 days.
- Claremont, NH 36 mi, 34.6 days
- Lebanon, NH 36 mi, 30.4 days
- Glens Falls, NY 39 mi, 27.7 days
- Saratoga Springs, NY 55 mi, 24.7 days
- Keene, NH 57 mi, 27.8 days
Where these numbers come from
NOAA 1991–2020 climate normals from Rutland, 1.1 miles from Rutland. 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.