Wind damage is the number-one enemy of metal roofs. They’re lightweight unless they have standing seam metal density (which most won’t). Unfortunately, metal roof wind resistance for corrugated metal roofs are weak, but the best roofers in London ON will definitely have reliable solutions you can depend on to secure it in place.
However, it can be alarming reading how corrugated metal roofs blew off like banana peels in the news. We recently read about this feature in Nova News Now. A barn in Nova Scotia blew its metal roof right off after tropical depression Dorian had overcome the material’s metal roof wind resistance. According to the news, the Willowbank U-Pick farm owner was appalled at the destruction the storm caused.
Poor Metal Roof Wind Resistance: Willowbank U-Pick Farm’s Metal Roof Issue
Andrew Johnson of Willowbank U-Pick Farm, located just outside Port Williams on the Starrs Point loop, said he was expecting Dorian to cause significant damage to the apple crop. It was vulnerable given the time of year. He didn’t foresee the wind tearing the metal roof off their barn, something he called “amazing.” The metal roofing was installed some 20 years ago and had survived all major wind storms since.
“It’s surprising, that barn’s been there for an awful long time,” Johnson said. “It just got underneath one corner of that roof and just peeled it off like a banana.”
He said the wind started to lift the metal roofing off around the same time they lost power, at approximately 2 p.m. on Sept. 7. (Continued)
If you’ve read through the full post above, you may have read somewhere that their corrugated metal roof is at 20 years of age. A corrugated tin or steel roof’s lifespan is about 50 years. In turn, any professional will say that the roof needed some maintenance work especially in improving its metal roof wind resistance or a full-on replacement to protect against severe winds.
However, the article above did not describe whether the roof was aluminum or steel. Using the latter will help against wind resistance because aluminum has lighter weight. In turn, this can cause undesirable wind lifts that aid in the destruction of the roof. Additionally, Science Daily explains how the roof shape itself, will contribute to improving wind damage resistance.
Metal Roof Wind Resistance: Which Roof Designs Prevent Wind Damage
Certain home shapes and roof types can better resist high winds and hurricanes, according to a researcher at New Jersey Institute of Technology (NJIT). Civil engineer Rima Taher, PhD, special lecturer in the New Jersey School of Architecture at NJIT. She spent two years examining the findings of research centers that have studied the best designs and construction materials and methods needed to withstand extreme wind events and hurricanes.
“Although I’d like to say that there is a simple and economical solution for housing that won’t fail or collapse in the perfect storm, such information does not yet exist,” said Taher. “However, it is obvious that thanks to the work of wind engineers and researchers that changes to home design and construction can make buildings safer for people, while saving government and industry billions of dollars annually.”
“Design of Low-Rise Buildings for Extreme Wind Events” (Journal of Architectural Engineering, March, 2007) by Taher highlighted such research findings. Wind researchers at the Center for Building Science and Technology (CSTB) in France, researched and tested reduced-scale home models at its wind tunnel facilities, and developed a prototype of a “cyclonic” or hurricane-resistant dwelling. Taher cooperated with the CSTB wind researchers, working on the structural aspect of the home’s design. (Continued)
One last thing we’ve noticed about the barn’s roof is it is installed over shingles. While this has no effect on metal roof wind resistance, it limits the roof material’s attachment on the roof joists itself. Most contractors supportive of metal roof over shingles installations will debunk this by stating you can use long screws to put the materials in place. However, a full-on roof replacement will have given the barn a chance to have better metal roof wind resistance with its secured joists.
Seeing from the photos of the Willowbank U-Pick farm’s metal roof destruction, it is greatly possible they suffered from poor metal roofing foundational construction. Why did they install it on top of old asphalt shingles? Because it’s cheaper, as The Spruce explains below.
Metal Roofing Can Be Installed Over Existing Roofs
Metal roofs can be installed over your existing roof without tearing off shingles, provided local building codes allow it. While shingle removal is the preferred route, tear-off is messy and raises the cost of the job.
A potential problem with this type of installation is trapped water vapor. If trapped between the metal roofing and old roofing, moisture can build up and cause mold and rot. But roofers can install a vented metal roof that eliminates this potential problem. Or, installing the new metal roofing over furring strips (1 x 3s or similar) will raise the metal and provide a ventilating air pocket between layers.
Make sure to consult local buiding codes before having a metal roof installed directly over old shingles. Some jurisdictions may require full tear-off whenever a new roof is installed. (Read more)
To avoid having a similar problem with your roofing material, it’s essential to have professional roofers help prolong your metal roof wind resistance with an excellently-executed installation. If you have yet to find a reliable professional in London ON, you can count on Cub Roofing to help you. We have decades of experience that can surely deliver the caliber of roofing service you need. Contact us today!