Ice dam risk in Randolph Town, MA
Ice dams in Randolph Town, MA: how often
15.3 dam days a winter
High risk. On an ordinary house in Randolph Town, conditions for an ice dam come on about 15.3 days in a normal winter, mostly in January and February.
Randolph Town averages 70 inches of snow a year and about 56 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 Randolph Town
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 8.9 | Moderate |
| Typical, some insulation, not air-sealed | 15.3 | High |
| Older or poorly insulated, warm attic | 23.4 | High |
Sealing and insulating a typical attic takes out about 6.4 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 23.4 days.
What to do about ice dams in Randolph Town
- 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.
Which to spend on first: air sealing or heat cable.
Randolph Town winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 18.6 | 16.8 | 5.5 |
| February | 18.2 | 15.6 | 4.7 |
| March | 15.0 | 12.1 | 2.5 |
| April | 2.8 | 1.2 | 0.1 |
| October | 0.7 | 0.2 | 0.0 |
| November | 1.8 | 1.2 | 0.1 |
| December | 12.6 | 9.2 | 2.4 |
Randolph Town next to nearby towns
Randolph Town ranks 26 of 58 Massachusetts cities here for ice-dam days, behind Pittsfield at 31.3 days.
- Braintree Town, MA 3 mi, 11.2 days
- Weymouth Town, MA 6 mi, 11.2 days
- Quincy, MA 6 mi, 11.2 days
- Brockton, MA 7 mi, 7.6 days
- Boston, MA 11 mi, 10.4 days
Where these numbers come from
NOAA 1991–2020 climate normals from Blue Hill Coop, 3.9 miles from Randolph Town. 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.