Ice dam risk in Waterbury, CT
Ice dams in Waterbury, CT: how often
11.7 dam days a winter
Moderate risk. On an ordinary house in Waterbury, conditions for an ice dam come on about 11.7 days in a normal winter, mostly in February and January.
Waterbury averages 39 inches of snow a year and about 42 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 Waterbury
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 7.8 | Moderate |
| Typical, some insulation, not air-sealed | 11.7 | Moderate |
| Older or poorly insulated, warm attic | 16.6 | High |
Sealing and insulating a typical attic takes out about 3.9 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 16.6 days.
What to do about ice dams in Waterbury
- 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.
Waterbury winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 11.1 | 12.5 | 4.0 |
| February | 11.8 | 13.4 | 4.0 |
| March | 5.5 | 8.5 | 1.9 |
| April | 0.5 | 0.2 | 0.0 |
| October | 0.6 | 0.1 | 0.0 |
| November | 0.8 | 0.6 | 0.1 |
| December | 8.3 | 6.5 | 1.7 |
Waterbury next to nearby towns
Waterbury ranks 4 of 21 Connecticut cities here for ice-dam days, behind Torrington at 23.6 days.
- Naugatuck, CT 5 mi, 11.9 days
- Bristol, CT 10 mi, 11.7 days
- Meriden, CT 13 mi, 11.7 days
- Ansonia, CT 15 mi, 7.4 days
- New Britain, CT 15 mi, 11.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from Burlington, 17.2 miles from Waterbury. 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.