Asphalt shingles installed in winter usually do not seal on install day. Each shingle has a strip of factory sealant that bonds to the shingle above it once the sun warms the roof, and in cold weather that can take days, weeks or, on a shaded slope, until spring. Until then the nails and any hand sealing hold the shingles, and the roof often looks wavy. Both are normal. What you want to check is that the edges and ridge were hand-sealed, and that every shingle has bonded by the time warm weather arrives.
Why a new winter roof looks wavy
Shingles are packed flat and stacked in bundles. In the cold, asphalt is stiff, so a shingle keeps the slight curve it had in the bundle and on the roof it can look lumpy. As the roof warms, the asphalt softens and gravity pulls each shingle flat. Owens Corning notes that its SBS modified shingles, such as Duration FLEX, stay more pliable and resist splitting in less-than-ideal installation conditions; standard shingles get there too, just more slowly.
How the sealant strip works, and why cold delays it
Owens Corning calls the bond a thermal seal: heat activates the sealant. Its guidance on winter roofs says shingles may take longer to thermal seal in cold weather, may need additional hand sealing, and that projects may take longer depending on the weather. Our rule of thumb, learned over many Colorado winters, is that the roof surface matters more than the air: a roof in full sun can be well above the air temperature, while a shaded slope stays at it.
Colorado Springs helps here. National Weather Service normals (1991 to 2020) put the average high at 44.6 degrees in December, 45.0 in January and 46.5 in February, with lows near 18 to 20 degrees. The sunny afternoons are what let shingles start to seal mid-winter; the cold nights are why we never count on it.
What we do on a cold-day install
- Hand-seal shingles at the rakes, eaves, ridge and other wind-exposed areas with manufacturer-approved adhesive.
- Install a windstorm starter strip, part of our Integrity Roofing System, so the first course has a factory bond line.
- Store bundles per the manufacturer’s instructions so they are not stiff with cold when they go down.
- Skip high-wind days. An unsealed roof should not face its first gale on day one.
- Lay ice and water membrane on a clean, dry deck. Read how self-adhering underlayment behaves in the cold.
Your spring checklist
Once you get a few warm, sunny weeks, take ten minutes:
- Look at the roof from the street and the backyard. Waves should be gone. Lines of shingle edges that still stand up are worth a call.
- Check the edges and ridge after the first big spring wind. Creased or lifted shingles mean that spot did not seal.
- Walk the yard. A shingle tab or ridge cap on the ground is the clearest sign.
- Look in the attic after a heavy rain or snowmelt for any new staining.
- Call us with photos if anything looks off. Resealing is quick when it is caught early.
Planning a winter roof?
If you are still deciding whether to schedule now or wait, our winter roof installs page covers the PPRBD rules and the pros and cons, and can you install roofs year-round in Colorado? compares the seasons. The shingle itself matters too: see the Owens Corning shingles we install.
Integrity Roofing and Painting is veteran-owned and family-run since 1990, an Owens Corning Platinum Preferred contractor with 650+ Google reviews. Call (719) 488-2800 or book a free Colorado Springs inspection; we reach out the same business day.
Sources: Owens Corning, Can You Get a New Roof or a Roof Repair in the Winter?; National Weather Service Pueblo, Normals and Extremes, Colorado Springs (1991 to 2020 normals).
