Ice dam risk in Arvada, CO
Will your roof get ice dams in Arvada, CO?
13.3 dam days a winter
Moderate risk. On an ordinary house in Arvada, conditions for an ice dam come on about 13.3 days in a normal winter, mostly in December and January.
Arvada averages 76 inches of snow a year and about 55 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 Arvada
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 11.1 | Moderate |
| Typical, some insulation, not air-sealed | 13.3 | Moderate |
| Older or poorly insulated, warm attic | 16.1 | High |
Sealing and insulating a typical attic takes out about 2.2 days a winter here. It does not move the risk band, but it shortens every dam.
What to do about ice dams in Arvada
- 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.
Arvada winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 9.6 | 12.5 | 3.4 |
| February | 11.9 | 10.3 | 2.8 |
| March | 12.9 | 5.8 | 1.3 |
| April | 12.1 | 3.7 | 0.5 |
| May | 2.2 | 0.6 | 0.0 |
| September | 1.0 | 0.3 | 0.0 |
| October | 5.9 | 2.0 | 0.2 |
| November | 10.0 | 7.1 | 1.6 |
| December | 9.9 | 13.1 | 3.6 |
Arvada next to nearby towns
Arvada ranks 6 of 53 Colorado cities here for ice-dam days, behind Steamboat Springs at 51.0 days.
- Wheat Ridge, CO 5 mi, 13.3 days
- Westminster, CO 6 mi, 7.7 days
- Superior, CO 7 mi, 11.4 days
- Golden, CO 7 mi, 10.6 days
- Federal Heights, CO 7 mi, 7.7 days
Where these numbers come from
NOAA 1991–2020 climate normals from Wheat Ridge 2, 4.4 miles from Arvada. 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.