What cold does to a roof going on
Shingles stop sealing themselves
Every asphalt shingle has a strip of sealant along its underside. In warm weather the sun softens it and it bonds the shingle to the one below, which is what keeps the roof from lifting in wind. In cold weather that bond does not form until the weather warms up — which in a Connecticut winter can be weeks. The manufacturers’ answer is hand-sealing: a dab of roofing cement under each shingle, to their printed instructions, so the roof is held down from the day it goes on.
Shingles get stiff
A cold shingle is less flexible. Bent hard over a ridge or nailed carelessly, it can crack. That is why bundles are kept somewhere warm until they are used, why the crew works in sections, and why the ridge and hip caps are handled with more care than they would be in July.
Membranes need a dry deck
The ice barrier at the eaves and the membrane strips over the deck joints are self-adhering — they stick because the adhesive bonds to the wood. Frost, ice or a wet deck stop that bond, and each manufacturer publishes the conditions its membrane can be applied in. In winter the deck is dried and cleared before anything goes down, and work waits for the day to warm up rather than starting at first light on a frozen roof.
What Connecticut’s code still requires in January
The code does not take the winter off. Connecticut enforces the 2022 Connecticut State Building Code, based on the 2021 International Residential Code, and puts the whole state in climate zone 5A with a 7°F winter design temperature. A new roof still needs an ice barrier at every eave (IRC R905.1.2), Connecticut’s self-adhering strip over every deck joint (R905.1.1 as amended), a drip edge at eaves and rakes (R905.2.8.5), and new flashing wherever the old is worn (R908.5). The winter roof and the summer roof are built to exactly the same standard. See asphalt shingle roofs for what each of those parts does.
How a winter roof is installed properly
- Only what can be closed the same day comes off. The house is never left open overnight. If the weather turns, the crew stops and the section is weathertight before they leave.
- The deck is dried and cleared of frost, ice and snow before any membrane goes down.
- Shingles are stored warm and brought up as needed.
- Shingles are hand-sealed to the manufacturer’s cold-weather instructions rather than left to seal on their own.
- Snow and ice days are not work days. A roof covered in snow cannot be worked on safely or properly, so a winter schedule moves with the weather. We will tell you plainly when that happens.
When a job should wait for spring
Most shingle roofs can go on in winter. Some work is better left for warmer weather: some flat-roof membranes and their adhesives have their own temperature limits, and large jobs that would leave a lot of roof exposed for several days are easier to protect in spring. If a roof is not actively failing, waiting a few months is often the simpler choice. If it is leaking, tarping it now and replacing it on the first good stretch of weather is usually the right answer. We will tell you which one your roof is.
Leaks in the middle of winter
Most winter leaks in Connecticut are ice dams, not holes: snow melts on the warm upper roof, refreezes at the cold eave and backs water up under the shingles. The fix is in the attic as much as on the roof. See ice dams and what to do when a roof leaks. A roof that has been damaged and is letting water in can be tarped the same day while a proper repair is scheduled.
What a winter estimate should spell out
A roofer quoting winter work should be able to put the cold-weather method in writing, not just say “we do roofs all year.” Look for: how the shingles will be sealed, how the deck will be dried before the membranes go down, what happens on a snow or ice day, how the roof is protected if work stops partway, and whether the price changes if the weather pushes the schedule. If an estimate for January reads exactly like one for July, ask why.
Why some people choose winter on purpose
Roofing has a busy season, and it is not winter. A roof replaced between storms in January is often scheduled sooner than one booked for the middle of summer, and getting a failing roof done before the spring rains is worth a lot. What it should not mean is cutting corners on the cold-weather steps above — ask any roofer quoting winter work how they handle sealing and membranes, and expect a specific answer.
Roof failing before spring?
Free inspection, a straight answer on whether it can wait, and a winter installation done to the manufacturer's cold-weather instructions.
Common questions about winter roofing
Can a roof be replaced in winter in Connecticut?
Yes. Roofs are replaced through Connecticut winters every year. Shingles are hand-sealed to the manufacturer's cold-weather instructions, membranes go on a dry, frost-free deck, and the house is never left open overnight.
Do shingles seal in cold weather?
Not on their own. The sealant strip under each shingle needs the sun's heat to bond, so in cold weather manufacturers call for hand-sealing each shingle with roofing cement.
Is a winter roof as good as a summer roof?
Yes, when it is installed to the manufacturers' cold-weather instructions and to the same code. Connecticut's requirements, including the ice barrier at every eave, apply in January exactly as they do in July.
What happens if it snows during my roof replacement?
Work stops and the open section is made weathertight before the crew leaves. A snow- or ice-covered roof cannot be worked on safely, so a winter schedule moves with the weather.
Should I wait until spring to replace my roof?
If the roof is not leaking, waiting can be the simpler choice. If it is failing, it can be tarped now and replaced on the first good stretch of weather, or replaced in winter properly.
Why is my roof leaking only in winter?
Almost always an ice dam. Heat from the house melts snow on the upper roof, it refreezes at the eave, and melting snow backs up under the shingles. See our page on ice dams.