· by Michael Blair, Nashville's Roofers
Most asphalt shingles carry a thermally activated sealant that bonds them together once they are on the roof, and how long that takes depends on the slope, which way it faces and how much sun and heat the shingles get, as the Asphalt Roofing Manufacturers Association’s cold-weather bulletin puts it. So the temperature at installation genuinely matters. Our own calendar, meanwhile, follows the storms. In Middle Tennessee those two point at different months, and knowing both is how you pick a good one.
Why does temperature matter when shingles go on?
Atlas Roofing’s cold-weather installation bulletin says the sealant bonds after a few weeks of sufficient heat from sunlight, and that shingles installed in fall or winter without adequate surface temperatures may never seal at all. Those have to be hand sealed at installation, with one or two spots of roofing cement under every tab, and the bulletin singles out rakes and eaves as especially prone to blowing off when they are left unsealed. Cold also makes the shingle itself stiff: Atlas says they become less flexible at about 40°F and can crack when bent or dropped. Here that window is real. The National Weather Service’s Nashville climate page puts the average first freeze around November 11 and the last around March 31, with 15 or more nights at or below 32°F in each of December, January and February.
Very hot days cause the opposite problem. In hot weather the asphalt coating softens and scuffs under foot traffic, and ARMA’s hot-weather bulletin advises installing early in the day, before the temperature peaks, working the west- and south-facing slopes in the morning and the rest after. The NWS normals for Nashville run 87.7°F in June and above 90°F in July and August, against 72.6°F in April, 80.4°F in May, 84.4°F in September and 73.5°F in October. Somewhere in the mid-70s to mid-80s is where we would rather be working, which here means late spring and early fall.
When are roofing crews busiest in Nashville?
In our experience spring storm season fills the schedule with insurance work, and that is when the wait for a start date is longest. Storm jobs usually run alongside a claim, which our storm damage page walks through. Late summer into fall brings a second rush, from homeowners who want the roof done before winter.
Late fall and winter are quieter for us, and open dates are easier to find. The cost is a narrower weather window: the NWS normals average 8 nights at or below freezing in November and 16 in December, and every one of those cold-season roofs raises the sealing question.
The genuine sweet spots here
Late September into October is the best combination in Middle Tennessee. Normal highs ease from 84.4°F to 73.5°F across those two months, the normals show no freezing nights in September and one in October, and a roof finished then still gets a few weeks of fall sun before the average first freeze in mid-November.
Late winter into early spring is the flexible option. February averages 15 nights at or below freezing and March 8, so a roof in those months is one we plan to hand-seal, on a schedule that moves with the weather, and in our experience it is easier to get a start date then. One caution if the plan is a second layer: ARMA warns that shingles laid over an uneven surface in cold weather may have that unevenness locked in, even after it warms up. That is worth weighing alongside the rest of our post on roofing over the old shingles or tearing off.
- Late September to October: warm days, almost no freezes, weeks of sun before winter
- February to March: easier start dates, with hand-sealing and weather delays
- April to June: storm season, and in our experience the longest wait
- Deep winter: possible on dry, frost-free days, with every tab hand-sealed
What actually decides it
A roof that is leaking does not get to wait for a season. Water keeps reaching the decking, the insulation and the ceiling below for as long as the leak is open, so the leak goes to our roof repair crew first and the replacement gets planned once the house is dry.
A roof that is simply near the end of its life can be planned, and planning is where the choice of month comes back in. Inside Metro Nashville a new roof needs a building permit, while repairs to no more than 33 percent of the roof area do not, according to Metro Codes’ residential permit page. Getting quotes in January for a roof replacement in March is a very different conversation from calling in May after a storm, and you can ask us for a free estimate whenever you want to start it.
Sources
- Asphalt Roofing Manufacturers Association, Recommendations for Installation of Asphalt Roofing Shingles in Cold Weather (revised March 2022) — Thermally activated sealant; sealing time depends on slope, orientation and sun; wait for a roof free of ice and frost; cold overlays may lock in an uneven surface
- Atlas Roofing, Cold Weather Shingle Installation Recommendations (technical bulletin) — Sealant needs a few weeks of sun; fall and winter installs may never seal and must be hand sealed, every tab; rakes and eaves prone to blow-off; less flexible at about 40°F
- Asphalt Roofing Manufacturers Association, Storage and Application of Asphalt Roofing Shingles in Hot Weather (revised February 2024) — Asphalt coating softens and scuffs in heat; install early in the day; work around the sun
- National Weather Service Nashville, Nashville climate (BNA normals) — Monthly normal highs; average days at or below 32°F; average first and last freeze dates
- Metro Nashville Codes, Residential Building Permits — Permit required to install roofing; repairs up to 33 percent of the roof area exempt
FAQ
The Best Time of Year to Replace a Roof — questions
Can a roof be replaced in winter in Nashville?
Yes, on the right days. ARMA advises waiting until the roof surface is free of ice and frost, which can be nearly invisible in winter, and cold shingles are stiff enough to crack if they are bent or dropped. The bigger issue is sealing. Shingles laid in fall or winter without enough sun may never seal on their own, so Atlas Roofing calls for hand-sealing every tab with roofing cement at installation. Done that way, a winter roof is a reasonable choice, provided the roofer plans for it.
Is it cheaper to replace a roof in the off season?
We would not plan around a seasonal discount, because we have no figure for one we would stand behind. What the quieter months give you, in our experience, is availability: more choice of start date and a crew that is not working through a storm backlog. Compare quotes on the same scope of work, whatever the month.
How long does a roof replacement take?
It depends on the size and pitch of the roof, how many layers come off and how much decking needs replacing once the old shingles are up. Weather is the main variable, and on hot days we start early and work around the sun. Ask for the expected number of days on your roof when you get the quote. What should not be rushed is the flashing and penetration work, which is where the roof either leaks or does not.
Which month is best for a new roof in Middle Tennessee?
Late September into October. Normal highs ease from about 84°F to 73°F, the normals show almost no freezing nights, and the shingles still get weeks of sun to seal before the mid-November first freeze. Late winter into early spring is the flexible second choice, with hand-sealing and weather delays.