Ice dam risk in Bluffton, IN
Ice dams in Bluffton, IN: how often
10.6 dam days a winter
Moderate risk. On an ordinary house in Bluffton, conditions for an ice dam come on about 10.6 days in a normal winter, mostly in January and February.
Bluffton averages 23 inches of snow a year and about 35 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 Bluffton
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 5.4 | Moderate |
| Typical, some insulation, not air-sealed | 10.6 | Moderate |
| Older or poorly insulated, warm attic | 17.0 | High |
Sealing and insulating a typical attic takes out about 5.2 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 17.0 days.
Preventing ice dams on a Bluffton 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.
Which to spend on first: air sealing or heat cable.
Bluffton winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 7.6 | 12.6 | 4.4 |
| February | 6.5 | 10.3 | 3.2 |
| March | 3.6 | 3.5 | 0.7 |
| April | 0.4 | 0.2 | 0.0 |
| November | 1.1 | 1.0 | 0.2 |
| December | 4.1 | 7.4 | 2.1 |
Bluffton next to nearby towns
Bluffton ranks 36 of 88 Indiana cities here for ice-dam days, behind Plymouth at 15.9 days.
- Decatur, IN 14 mi, 11.4 days
- Huntington, IN 20 mi, 10.5 days
- New Haven, IN 24 mi, 11.4 days
- Fort Wayne, IN 24 mi, 11.4 days
- Marion, IN 29 mi, 8.8 days
Where these numbers come from
NOAA 1991–2020 climate normals from Bluffton 6N, 5.0 miles from Bluffton. 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.