Ice dam risk in Glenwood Springs, CO
Ice dams in Glenwood Springs, CO: how often
15.9 dam days a winter
High risk. On an ordinary house in Glenwood Springs, conditions for an ice dam come on about 15.9 days in a normal winter, mostly in January and December.
Glenwood Springs averages 39 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 Glenwood Springs
| Attic | Dam days | Risk |
|---|---|---|
| Air-sealed and well insulated | 11.6 | Moderate |
| Typical, some insulation, not air-sealed | 15.9 | High |
| Older or poorly insulated, warm attic | 21.3 | High |
Sealing and insulating a typical attic takes out about 4.3 days a winter here. It drops the risk from high to moderate. An older house with a warm attic should expect closer to 21.3 days.
Preventing ice dams on a Glenwood Springs 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.
Which to spend on first: air sealing or heat cable.
Glenwood Springs winter, month by month
| Month | Snow (in) | Days on ground | Dam days |
|---|---|---|---|
| January | 13.7 | 21.6 | 6.7 |
| February | 6.3 | 13.5 | 3.5 |
| March | 2.4 | 2.1 | 0.4 |
| April | 0.6 | 0.7 | 0.1 |
| October | 0.7 | 0.8 | 0.1 |
| November | 4.4 | 2.4 | 0.6 |
| December | 10.8 | 14.4 | 4.5 |
Glenwood Springs next to nearby towns
Glenwood Springs ranks 5 of 53 Colorado cities here for ice-dam days, behind Steamboat Springs at 51.0 days.
- Rifle, CO 23 mi, 16.6 days
- Steamboat Springs, CO 70 mi, 51.0 days
- Grand Junction, CO 73 mi, 6.9 days
- Fruita, CO 79 mi, 6.2 days
- Montrose, CO 79 mi, 10.1 days
Where these numbers come from
NOAA 1991–2020 climate normals from Glenwood Spgs #2, 0.6 miles from Glenwood Springs. 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.
- Snow-on-the-ground counts come from a second, nearby station, because the closest one does not record them.