Ice dam risk in Lebanon, IN
Will your roof get ice dams in Lebanon, IN?
7.6 dam days a winter
Moderate risk. On an ordinary house in Lebanon, conditions for an ice dam come on about 7.6 days in a normal winter, mostly in January and February.
Lebanon averages 22 inches of snow a year and about 28 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 Lebanon
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 4.1 | Low |
| Typical, some insulation, not air-sealed | 7.6 | Moderate |
| Older or poorly insulated, warm attic | 12.0 | Moderate |
Sealing and insulating a typical attic takes out about 3.5 days a winter here. It drops the risk from moderate to low. An older house with a warm attic should expect closer to 12.0 days.
What to do about ice dams in Lebanon
- 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.
Which to spend on first: air sealing or heat cable.
Lebanon winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 7.2 | 11.1 | 3.6 |
| February | 6.8 | 7.7 | 2.1 |
| March | 2.4 | 2.0 | 0.3 |
| April | 0.2 | 0.1 | 0.0 |
| October | 0.1 | 0.0 | 0.0 |
| November | 0.6 | 0.6 | 0.1 |
| December | 4.7 | 6.1 | 1.6 |
Lebanon next to nearby towns
Lebanon ranks 56 of 88 Indiana cities here for ice-dam days, behind Plymouth at 15.9 days.
- Whitestown, IN 7 mi, 7.6 days
- Zionsville, IN 8 mi, 7.6 days
- Brownsburg, IN 15 mi, 7.0 days
- Westfield, IN 16 mi, 7.6 days
- Carmel, IN 17 mi, 8.1 days
Where these numbers come from
NOAA 1991–2020 climate normals from Whitestown, 6.3 miles from Lebanon. 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.