The Hill Country doesn't get many hard freezes, and that's precisely the problem. Homes in Minnesota are built for it. Homes in Boerne are not, and the infrastructure that protects a northern house from ice simply isn't present here.
February 2021 demonstrated what that looks like at scale. Here's what's worth doing before the next one.
What actually goes wrong on a Texas roof in a freeze
- Ice damming. Heat escaping an under-insulated attic melts snow on the upper roof. The meltwater runs down to the cold eave, refreezes, and builds a dam. Water then backs up under the shingles, which are designed to shed water downhill, not to hold it. This is the mechanism behind most freeze-related roof leaks here.
- Gutter and downspout freezing. Debris-clogged gutters hold water that freezes solid, adding weight, tearing gutters loose, and blocking the drainage path that would otherwise prevent damming.
- Attic plumbing. Not strictly roofing, but it's where enormous freeze losses come from. Pipes running through unconditioned Texas attics have minimal insulation because they never needed it.
- Thermal shock on aging shingles. Brittle, heat-aged shingles crack under rapid temperature swings. A roof at year eighteen going from 75°F to 15°F in a day takes real damage.
- Snow and ice load. Rarely structural here, but accumulation on low-slope porch and patio roofs is worth watching.
The single highest-value thing: attic insulation
Ice dams are fundamentally an insulation problem, not a roofing problem. They form because the roof deck is being warmed unevenly from below.
If your attic insulation is thin, settled, or missing over parts of the ceiling plane, that's the fix that actually prevents damming. It also pays for itself every summer — the same deficiency that lets heat escape in January lets heat pour in during July. Our attic insulation guide covers the right sequence.
Ventilation still matters in winter
People assume ventilation is a summer concern. In a freeze it's what keeps the roof deck uniformly cold, which is what prevents the melt-refreeze cycle. A well-ventilated attic has fewer ice dam problems than a sealed one, counterintuitive as that sounds.
A pre-freeze checklist
- Clear gutters and downspouts completely. This is the highest-value hour you'll spend. A clear drainage path is the difference between water leaving and water pooling and freezing.
- Check that downspouts discharge well away from the foundation and aren't blocked at grade.
- Get insulation to proper depth, particularly over the ceiling plane and at the attic hatch.
- Confirm soffit vents are open and not blocked by insulation.
- Insulate attic plumbing runs and know where your main shutoff is.
- Address deferred roof repairs now. A marginal roof at 70°F is a leaking roof at 20°F.
- Trim limbs. Ice loading brings down branches that would hold up fine in wind.
During a freeze
Don't get on the roof. An iced roof is genuinely lethal, and nothing up there needs doing badly enough to justify it.
Don't chip at ice dams with anything sharp — you'll destroy the shingles underneath and turn a temporary problem into a permanent one. If water is coming in, contain it inside and call once conditions are safe.
If a ceiling is bulging with trapped water, a small relief hole over a container prevents a much larger collapse. Our emergency page covers that.
After it thaws
Get an inspection. Freeze damage frequently doesn't show up until the next significant rain, because the failure is a cracked shingle or a lifted seal rather than an open hole. A documented post-freeze inspection also establishes a date of loss if you end up filing.
Free inspections
We'll assess your roof, attic insulation and ventilation together, since all three determine how your house handles a freeze. Request an inspection or call (210) 245-4125.
