Uplift, Scouring, and Wind – How Winter Effects Your Commercial Roof
When you think of the effect that winter weather has on your commercial roof, wind might be on your list, but probably after rain, snow, hail, and/or intense sunlight. Because winter can be a season of strong winds, keep in mind that they can also be damaging to your roof, in more than one way. Here are some examples.
When the wind blows across your flat commercial roof, it creates an uplift – much like the effect that gives an airplane wing its lift. Relatively higher air pressure from inside the building below pushes against the roof membrane – the stronger the wind, the stronger the uplift pressure. You may see this showing up as wrinkles or blisters on the surface of the membrane. Some wrinkling from uplift is to be expected as part of the normal rooftop environment. But multiple episodes of strong uplift can separate your roof membrane from the deck below, which can lead to a loss of the roof’s integrity and leaks.
Strong winds can also exploit imperfections at membrane seams on deck sheets and flashings. A small gap can provide enough surface area for wind forces to “grab” and pull apart, creating opportunities for water to get underneath the membrane.
Another potential area for wind damage is at the perimeter of your roof. Most commercial roofs have metal or plastic components around the perimeter of the building – fascia, gutters, termination strips, and other edge details. Sections of these components can separate from each other as well as become detached from the building, putting the secure attachment of your roofing system at risk. Pieces that come completely loose can become hazards to people on the ground.
Repairing excessive blistering, re-seaming membrane sections, and ensuring edge components are secured: any of these situations should be addressed by a professional commercial roofing contractor, who has the tools and experience to do it properly.
A different problem, and one that your maintenance team should be able to take care of, is when roof ballast has been redistributed following one or more wind events. Ballast is often a component of built-up and EPDM roofing systems and can be moved across the surface by strong winds – an effect called scouring. The movement of the stone can damage the surface underneath, as well as leave it exposed to the weather. After a storm, your crew should make sure that the ballast is spread evenly across the rooftop.
Spring, summer, fall, or winter, Diversified Services is prepared to help you with your commercial roofing needs. Contact us today.