Ice Dam Roof Damage: Why It Happens in Santa Fe

During a Santa Fe winter, you’ll get sunny afternoons followed by freezing evening temperatures. In other words: We get the perfect conditions for ongoing freeze-thaw cycles. 

Enter the ice dam. 

Ice dams are a problem that can lead to leaks, damaged insulation, stained ceilings, and deteriorating roofs. They can occur both on pitched roofs with eaves and on the classic Santa Fe flat or low-sloped roof, with winter drainage and ice issues impacting roof edges, low spots, and drain systems including canales. 

Let’s look at how this works, and how you can be proactive: 

First: What is an ice dam? 

An ice dam is simply a ridge of ice — often near the roof edge — that blocks meltwater from draining (as would any dam). 

This occurs when snow melts towards the middle of the roof, runs down to lower lying, colder edges, and then refreezes. Although the mechanism for this is most obvious for roofs with a high pitch, it also can be a big problem for low-pitched and flat roofs like what we commonly see in Santa Fe, particularly when it comes to snowmelt pooling and blocking canales. 

Once this begins, it often is the start of a cycle of melt flowing to roof edges or low points, not having anywhere to drain, and refreezing — the longer this cycle continues, the worse it’s exacerbated and the worse the buildup gets. Subsequently, water starts to back up and can cause leaking and damage. 

When it gets to this point, some of the most common types of damage are: 

• Interior leaks (on the ceiling or walls) 
• Wet insulation 
• Mold 
• Damaged Canales and gutters 

Root causes of ice dams 

This all starts because, as energy efficient as we can make modern homes, no home is 100% perfectly insulated — this means some amount of heat will escape from the house and warm the roof. 

When this happens, attic and ceiling heat loss escapes to the roof and melts snow from below. This can be exacerbated from Santa Fe’s large temperature swings and strong winter sun, which can add another relatively intense heat source from on top, too, accelerating this snowmelt. 

Air leaks can increase this problem too; warm air can leak into roof cavities through, for example: 

• Recessed lights 
• Plumbing or vent penetrations 
• Chimneys 

This can create localized hot spots of intensified snow melt. 

Roof design factors that can trap snow and ice 

There are certain aspects of a roof’s design itself that can increase risk of developing an ice dam and other complications involving snowmelt runoff. For example: 

• Skylights 
• Clogged gutters and/or downspouts that hold water and ice longer 
• Complex rooflines with lots of valleys 
• North-facing roof sections and shaded areas — refreezing becomes a serious possibility here 

Of course, complicated rooflines aren’t super common in our part of New Mexico, but these other structural and environmental factors mean ice dams are still something we encounter quite often in flat and low-pitch roofs. 

Where ice dams show up 

Structurally, there are some usual suspects for ice dams. 

As we mentioned above, pitched roofs’ complex rooflines can be an issue particularly around eaves and valleys, but also near skylights, chimneys, low spots on flat roofs and around canales. 

On flat roofs, or roofs with gentler slopes like we see commonly in Santa Fe, ice dams are most often found by downspouts icing over, parapet edges and canales when meltwater refreezes, and when ponding freezes into ice by seams, stressing them and causing potential damage. 

Early warning signs of an ice dam 

Like with all potential causes of home damage, it’s much easier of a fix the sooner you catch it. To that end, here’s what to look for: 

• Icicles or heavy ice buildup along the roof — especially if this keeps repeating after storms 
• Water stains on the ceiling or walls after snow 
• Drip around skylights, exhaust vents, or chimneys 
• Uneven snow melt patterns 

If you start to notice any of these, definitely take note and keep an eye on it at the very least — or better yet, move to fix it ASAP. 

How to prevent ice dams 

When it comes to ice dams, it generally comes back to two factors: heat loss, and roof drainage. 

First, heat loss: 

As we established earlier, ice dams start when heat from the inside of the home rises, heats up the roof, and melts snow from the bottom up. To mitigate this, then, you have to address that heat loss. Primarily, this means making your home as energy efficient and well-insulated as possible; in particular, pay special attention to weatherstripping, can lights, plumbing stacks, and wiring penetrations as potential sources of heat loss. 

That addresses the “interior” factor causing ice dams. Then comes the exterior causes and exacerbating factors — namely, roof drainage and snow load. 

When it comes to this, it’s really important to keep drainage systems clear; when meltwater starts running from above snow pack, you need to provide it with a clear pathway off the roof so it can freely drain before freezing. 

When to call the professionals 

We’ll start by saying — and this goes for so many home-related things — if you have any uncertainty, it’s better safe than sorry by calling a professional. Sometimes you’ll be fine addressing a minor problem yourself, but here are some signs you should definitely get local roofing pros involved to make sure the issue doesn’t escalate into something worse: 

1. If you notice active leaking during snowmelt or the freeze-thaw cycle. This means it’s snowballed into something that’s more complex than you can likely address yourself. 
2. Repeated ice buildup in the same section of the roof, every winter. This suggests certain systemic problems that need to be diagnosed and fixed. 
3. Signs of wet insulation or mold. At this point, the issue goes beyond the surface and the solution will similarly take expertise. 
4. On a flat roof especially, if the drainage system or any ponding freezes over. For obvious reasons, this then prevents the draining you need from snowmelt and freeze-thaw moisture. 

Bottom line 

While Santa Fe architecture mostly avoids complex roofing valleys and pitches, low-pitch and flat roofs still see ice dams as a primary winter problem — especially with our natural cold winter nights plus sunny days, an environmental factor for ice dams to thrive. 

This means it’s still important to keep an eye on potential hazards during the fall and winter and to address ice dams and leaks as soon as you notice them forming. By doing so, you’ll help ensure any small issues don’t snowball into big, complicated, expensive problems down the line. 

And of course, for many, a helpful step towards this is proactive winter roof inspections — if that’s you, don’t hesitate to give Santa Fe Stucco & Roofing a call! With our winter inspections, we’re not just giving your home the all clear, but you the peace of mind that comes with it.