Roofing does not stop in October on Long Island. Storms, leaks and insurance timelines do not care that the days got short. But an asphalt shingle roof installed in late fall is a different job from one installed in July, and the difference comes down to a thin strip of glue.
This post explains what that strip does, why cold weather keeps it from working, what hand-sealing is, and why a roof we install in November gets a follow-up visit in spring. If you are weighing a cold-season roof replacement, this is what you should expect from any roofer who does it right.
The seal strip and what it does
Look at the back of an asphalt shingle and you will find a band of dark adhesive. On the roof, that band sits under the shingle above it. When the sun heats the roof, the adhesive softens and bonds the two shingles together.
That bond is what makes a shingle roof resist wind. Nails hold a shingle to the deck, but it is the seal strip that keeps the exposed tab from lifting in a gust. A roof where every tab is sealed behaves like a single surface. A roof where the tabs are not sealed is a field of small flaps, each one waiting for the right wind.
In summer, the roof reaches sealing temperature within days. The strips bond, and the installer never thinks about it.
Why cold weather changes the job
Seal strip adhesive needs warmth, and it needs sun on the roof surface, not just a warm air temperature. In late fall on Long Island, the sun is low, the days are short and the roof deck may never reach the temperature the adhesive needs for weeks at a time. North-facing slopes and shaded roofs are worse.
That leaves a window where the shingles are nailed down but not sealed. Winter wind arrives in that window. Shingles can lift, crease at the nail line, or in a strong storm blow off entirely. A roof that would have been fine in August can lose tabs in December for no reason other than timing.
Cold also makes shingles stiff. A shingle bent over a ridge or cut around a vent in cold weather can crack if it is handled roughly. Good installers keep bundles warm before they go up and work the shingles gently.
What the manufacturers say
Every major shingle maker publishes installation instructions, and they include cold-weather guidance. The details differ by brand and product line. Some give a temperature below which hand-sealing is required. Some describe how and where to place the adhesive. Some cover storage of bundles in cold weather.
We are not going to quote a single number here because it depends on which shingle is going on your roof. Check your shingle maker's installation instructions, or ask your roofer to show you the cold-weather section for the exact product being installed. Following those instructions is also what protects the manufacturer's warranty, so it is worth five minutes.
If your roofer says cold weather does not matter, that is the wrong answer.
What hand-sealing is
Hand-sealing means the installer does the job the sun would normally do. As each course goes on, a small dab of asphalt roofing cement is placed under each shingle tab, and the tab is pressed down into it. The spacing and amount follow the manufacturer's instructions. Too little and the tab is not held. Too much and the cement can squeeze out, stain the roof or interfere with the way the shingle lays.
The cement is applied with a caulk gun or a trowel, depending on the product. It bonds in cold weather where the factory strip will not. The result is a roof that is wind-resistant the day it is finished, instead of whenever the weather cooperates.
Hand-sealing takes time. It adds hours to a roof that would be a one-day job in summer. That is the honest reason late-fall roofs cost more days than summer roofs, and it is not a reason to skip it.
Where it matters most
Not every tab on every roof needs the same attention. Rakes and eaves catch the most wind, so edge shingles are always sealed by hand in cold weather. Ridges and hips are next. North slopes and shaded areas that will not see sun until March are treated more carefully than a south-facing slope that may still warm up on a sunny afternoon.
Starter strips, ridge cap and any shingles cut around penetrations are also hand-sealed, because cut edges do not have a factory strip in the right place.
The rest of a cold-weather install
Hand-sealing gets the attention, but a late-fall roof has a few other differences.
The deck has to be dry. Frost on the sheathing in the morning is water by noon under the underlayment. We do not lay underlayment or shingles over frost.
Underlayment and ice barrier have their own temperature rules. Self-adhered ice and water shield, which goes along eaves and in valleys, also relies on adhesive and has a minimum application temperature from its manufacturer.
Nailing matters more. Since the seal strip is not backing up the nails for a while, every nail has to be in the right spot and driven flush. High nails and nails through the wrong part of the shingle are a bigger problem in a cold install.
And if the roof came with storm damage, the paperwork runs alongside the work. Our post on the order to document storm damage covers what to photograph before anyone touches the roof.
Why the spring inspection matters
A roof installed in November has been through December, January and February without its factory seal strips fully bonded. The hand-sealing carried it. By April or May, the sun has done its part and the strips have set.
A spring walk confirms that. We check that tabs are bonded and not lifting, that edges and ridge held, that nothing creased or shifted in a storm, and that flashings and penetrations look the way they did when we left. If a tab did not seal, it gets sealed then.
It is a short visit. It is also the step that most often gets skipped, and the one that separates a cold-weather roof that lasts from one that starts shedding tabs in year two.
What about the rest of the house
Roof work in the fall often turns up the places where water gets into a house, and some of those are below the gutter line. If the roofer finds soft fascia, rotted sheathing at the eave or a leader dumping at the foundation, those deserve a look too. Our post on siding that meets the stoop shows one of the spots we find most often when we are already working on the exterior.
Need a roof before winter?
JDG Concrete & Construction in Centereach handles roofing, siding and gutters along with our concrete work, under Suffolk County Home Improvement License #HI-68303. If your roof cannot wait for spring, we will install it to the shingle maker's cold-weather instructions, hand-seal what needs it, and come back in spring to check. Call or text (631) 672-1618 or request a quote.
Frequently asked questions
Can you install asphalt shingles in November on Long Island?
Yes, with the right steps. Shingles can be installed in cool weather, but the factory seal strip may not bond until the roof warms up. Manufacturers publish cold-weather installation instructions, and they generally call for hand-sealing shingles that will not get enough warmth to seal on their own. Check your shingle maker's instructions for the specifics.
What is a shingle seal strip?
It is the band of adhesive on each shingle that bonds it to the shingle below. The adhesive activates with heat from the sun. Once it bonds, the shingles act as a single surface against wind. Until it bonds, each shingle is held only by its nails.
What does hand-sealing a roof mean?
The installer places small dabs of roofing cement under each shingle tab, following the manufacturer's spacing, so the tabs are glued down without waiting for the sun. It is slower than a normal install and it is why a late-fall roof can take longer than a summer one.
Why do I need a spring inspection on a roof installed in the fall?
A roof installed in cold weather has been through winter wind before its seal strips fully bonded. A spring walk checks that tabs are sealed, no shingles lifted or shifted, and the hand-sealed areas held. It is a short visit that catches small problems before they become leaks.
Should I wait until spring to replace my roof instead?
If the roof is leaking or has storm damage, waiting through winter usually costs more than a cold-weather install done correctly. If the roof is simply old and still dry, spring is a fine choice. We will tell you which situation you are in.
