Did you just spend thousands of dollars on a new asphalt shingle roof, only to notice some of your brand-new shingles lifting or flapping in the wind? Are you worried that they were installed incorrectly, could blow off during the next Seattle windstorm, or leave your home vulnerable to leaks before they ever have a chance to seal?
At RoofSmart, we install hundreds of roofs year-round in the Greater Seattle area, which sometimes means replacing an urgent, leaking roof during colder weather when shingles can take longer to seal. We recently encountered this exact problem after completing a November roof replacement: a windstorm arrived before one section of the new shingles had fully sealed, causing several of them to flap in the wind.
In this case study, I’ll explain why asphalt shingles can take longer to seal in cold weather, why roofers sometimes still need to install them during Seattle’s fall and winter months, and what happened when this customer’s new shingles were hit by strong winds before they sealed.
|
Situation |
Why It Happens |
What You May Notice |
What Your Roofer Should Do |
|
Shingles installed below 40°F |
Cold temperatures can make shingles brittle and slow the sealing process |
Shingles may remain unsealed longer than expected |
Monitor the shingles and give them an opportunity to seal as temperatures warm |
|
Cold shingles during installation |
Shingles can become brittle, increasing the risk of cracking or granule loss |
Cracking, damage, or difficulty installing the shingles |
Warm shingles before installation when cold-weather roofing is necessary |
|
New shingles haven't sealed yet |
The adhesive strips need sufficient warmth and time to activate |
Shingle edges may remain loose |
Allow additional time for sealing if the shingles are otherwise undamaged |
|
Wind hits before shingles seal |
Unsealed shingles are more vulnerable to being lifted by strong winds |
Shingles may flap or lift during a windstorm |
Inspect the affected area for damage |
|
Shingles flap slightly |
Wind can lift an unsealed edge |
Minor movement without the shingle folding over |
Determine whether the shingle is still intact or needs replacement |
|
Shingles fold completely over |
Strong winds can bend an unsealed shingle far enough to damage it |
Shingle is folded back or visibly damaged |
Replace damaged shingles rather than waiting for them to seal |
|
Problem affects one roof section |
Some areas may have been installed later or had less opportunity to warm and seal |
Only one portion of the roof may be lifting |
Inspect and repair the affected section rather than assuming the entire roof has failed |
|
Older shingles lose their seal |
Aging, granule loss, and deterioration can cause previously sealed tabs to release |
Older shingles begin lifting or flapping |
Evaluate the overall roof condition and whether replacement is approaching |
|
Shingles blow off |
Strong winds can remove shingles that haven't adequately sealed |
Missing roofing material |
Repair the missing shingles promptly and inspect the exposed area |
|
Emergency winter roof replacement |
Leaks, rot, or structural problems may make waiting for warmer weather impractical |
Roof must be replaced despite less-than-ideal temperatures |
Use appropriate cold-weather installation practices and address sealing problems promptly if they occur |
Asphalt shingles are typically meant to be installed in temperatures of 40 degrees or higher. During the summer in Seattle, this is usually no problem. However, in the fall and winter, the weather can dip below 40 degrees.
The reason that asphalt shingle manufacturers warn against installing their products when it’s less than 40 degrees is that it makes the shingles vulnerable to cracking and potentially being unable to seal.
There are ways to warm shingles up if you need to install them when it’s cold outside, but they aren’t guaranteed to keep the shingles at the right temperature throughout the installation process.
You can warm up the shingles by letting them sit in the sun, or in the truck with the heat on for a while before installing them. This can make a huge difference in protecting them from cracking or granule loss during installation, as long as they don’t get too cold again.
Even though fall and winter in the Greater Seattle area can get cold, temperatures rarely dip super low. It’s common to have mild weather that is still warm enough to safely and effectively install asphalt shingles.
Homeowners might want to install their shingles in the fall or winter for a number of reasons. Sometimes, fall or winter just happens to be when they decide to redo the roof. Other times, homeowners notice significant rot or roof leaks that require them to get an urgent roof replacement.
For example, we recently had a customer who discovered that some of the beams in his roof were rotting while in the process of hiring a roofing contractor to replace his roof. He ended up choosing us, but the beams needed to be custom-made, so that process took several months.
By that time, his roof urgently needed to be replaced due to the rot, but it also happened to be November, which is a cold and rainy time in the Seattle area. On a warmer day that’s not very rainy, your roofer should still be able to install new shingles on your roof if needed.
Shortly after that, there was a pretty good windstorm, and the customer noticed a bunch of the shingles were flapping around. Unfortunately, they had not had the chance to seal properly (it can take a few weeks in the colder weather) before the wind came in.
Thankfully, this issue was limited to just one particular section. It was probably one of the last sections that we did.
But the good news is that with the synthetic underlayment we used, even if the shingles flew off, it was protected from leaking.
Stuff like that happens, especially when you roof year-round. In this case, we had to do the roof replacement right away because the customer’s roof was leaking, had dry rot in the beams, and we were worried the house was going to fall in.
When the customer called to report that the shingles were flapping in the wind, we sent our crew out. They replaced a bunch of the shingles in that section so that the new ones would have a chance to seal.
So if the shingles completely flop all the way over, then the integrity of the shingle is gone. If it just flaps a little bit, it doesn't really damage the shingle as much as if it flaps all the way over.
So usually they're not going to flap all the way over unless it's an older roof and the glue tabs or the thermal tabs have popped their seals. That would happen because the shingles get old and the granules get kind of thin on it (this is an indicator that it’s time for a new roof).
The customer was concerned with the shingles’ ability to seal, but I made sure to explain to him that installing shingles in cold, rainy weather is possible and the shingles would still seal.
In this case, the wind disrupted our plans a bit, but our customer took the setback well. After going back and installing new shingles, his roof was back in good condition.
By the end, he was very happy with his new shingles and the beam replacement. He appreciated our attention to detail and was pleased that we fixed the unsealed shingle issue right away.
Shingles that haven’t sealed immediately don’t necessarily mean your new roof was installed incorrectly. In colder Seattle weather, the adhesive strips can simply need more time and warmer temperatures to activate. The bigger concern is what happens during that waiting period, especially if strong winds arrive before the shingles have fully sealed.
That’s what happened on this project. When a windstorm caused some of the new shingles to flap, we inspected the affected section and replaced the shingles that had been compromised. The important part was recognizing the problem and taking care of it before it could turn into something more serious.
Sometimes, as with this homeowner’s leaking roof and severely rotted beams, waiting until summer simply isn’t a safe option. If you’re facing a roof replacement during Seattle’s colder months, you should understand what could go wrong and what your roofer can do to reduce those risks.
Read “What Are the Risks of Installing Asphalt Shingles in Cold Weather?” to learn about the challenges of winter shingle installation in Seattle and what you should discuss with your roofing contractor before moving forward.