Ice dam risk in Pittsfield, MA
How often ice dams form in Pittsfield
31.3 dam days a winter
High risk. On an ordinary house in Pittsfield, conditions for an ice dam come on about 31.3 days in a normal winter, mostly in January and February.
Pittsfield averages 77 inches of snow a year and about 98 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 Pittsfield
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 17.6 | High |
| Typical, some insulation, not air-sealed | 31.3 | High |
| Older or poorly insulated, warm attic | 48.5 | Severe |
Sealing and insulating a typical attic takes out about 13.7 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 48.5 days.
Preventing ice dams on a Pittsfield 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.
- 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 247 kWh a winter in Pittsfield, roughly $42 at 17 cents a kWh.
Which to spend on first: air sealing or heat cable.
Pittsfield winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 19.3 | 26.1 | 9.7 |
| February | 18.2 | 25.7 | 8.8 |
| March | 13.8 | 20.1 | 5.3 |
| April | 4.0 | 3.0 | 0.5 |
| May | 0.1 | 0.0 | 0.0 |
| October | 0.4 | 0.2 | 0.0 |
| November | 4.6 | 3.7 | 0.7 |
| December | 16.7 | 19.5 | 6.2 |
Pittsfield next to nearby towns
Pittsfield ranks 1 of 58 Massachusetts cities here for ice-dam days, the worst in the state.
- North Adams, MA 17 mi, 31.3 days
- Troy, NY 29 mi, 17.0 days
- Watervliet, NY 30 mi, 17.0 days
- Albany, NY 31 mi, 17.0 days
- Northampton, MA 31 mi, 15.9 days
Where these numbers come from
NOAA 1991–2020 climate normals from Worthington, 17.9 miles from Pittsfield. 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.