David Harrison and Jeremiah Robinson, V2T
V2T is a revolutionary wind-ballasted roof system which utilizes patented vent technology to firmly hold single-ply roof systems in place, even under extreme conditions. Various forces of physics apply to hold the roof in place with exponentially greater force as wind speed increases.
Low pressure above roofs along their perimeters is caused by vortexes that occur when wind hits the building. This pressure is generally what causes roofs to fail in wind events and is the reason why roofs typically fail at the perimeter first.
Most other wind-ballasted roof systems commonly seen in the market use one-way vents to channel these naturally occurring pressures under the membrane. The vents are strategically placed near the perimeter, which allows them to equalize the pressure above and below the roof surface. Since there is no differential in pressure, there is no uplift created by the natural vortex. These systems have been in place for many years and, when proper air seals are maintained, are extremely effective.
What makes V2T different is the vent design and a little help from physics, specifically the Bernoulli principle and the Venturi effect. These principles are related to one another and are as tested and proven as gravity. There are numerous resources for researching these principles on your own or you can always contact V2T if you want a more in-depth physics lesson as it applies to commercial roofing.
The bottom line is that because of their unique shape, the V2T vents speed up the wind (Venturi effect) and create a vacuum (Bernoulli's equation) every time wind or air moves through them. Because of the nature of the physical forces involved, this pressure increases exponentially as the velocity of the air (which acts as a fluid) increases. In simple terms, V2T vents flip the script and use natural forces against themselves. Essentially, the vents create greater pressure differentials by accelerating the wind.
The vacuum created in this pressure differential pulls air out of the roof system since the system is installed with air seals this creates a lower pressure below the membrane than above. By utilizing the Venturi effect, we accelerate the wind through the vent. Therefore, at a given ambient wind speed, the negative pressure produced by the vent comes from the higher wind speed surrounding the vent because of natural acceleration as air passes through the Venturi shape.
Because we lower the pressure within the roof system, those same forces that typically pull up on the edge of a roof are now pushing down. The V2T roof system does not equalize pressure in order to eliminate the effects of uplift, it essentially creates downward pressure, meaning that the area of low pressure created at a roof's
edge is actually higher than the pressure within the roof system due to the Venturi effect of the vents. Now, gravity is stronger than the "low pressure" area at the roof's edge, so it exerts its full force across the low-pressure area to firmly hold anything beneath the surface in place.
Besides not having to handle thousands of pounds of ballast, there is another advantage to all wind-ballasted
roof systems. Because they are loose-laid and not physically attached all over the roof area, the effects of uplift are spread over the entire roof area. Typically, wind comes from one direction at a time and therefore the forces created are stronger where the wind initially comes in contact with the building. Wind-ballasted systems redistribute those forces evenly across the roof, reducing strain and pressure on some roofing components more than others.
A key difference between V2T and other vented/ wind-ballasted roof systems is that we work exclusively with some of the most respected and largest roof system manufacturers in the US. These manufacturers offer the
V2T system as part of their lineup. You cannot buy a V2T roof independently; you must buy a roof from a participating manufacturer (Carlisle, FiberTite, Versico, Flex). These manufacturers provide the same warranties on a V2T wind-ballasted system as they do for any other roof system they sell (up to 20-year, total system, and no-dollar-limit warranties are available). We believe that top roofing system manufacturers are good at what they do. Showing their full support for our system by including it within their own product offerings is a testament to what the V2T system represents to the roofing industry.
Now you know what V2T is, but why does it matter to you? And why would you want a V2T roof for your next
project?
One of the easiest ways to sell a roof is typically by reducing cost. If you can provide a roof with the same performance at a lower price than your competition, it gives you a clear advantage. V2T excels in this area, especially with concrete, gypsum, or tectum decks. If you are working with one of these deck types, mechanical attachments are difficult and labor intensive, and quality roofing adhesives are expensive. V2T takes advantage of these sealed deck applications by requiring very few enhancements for proper installation. Without
sacrificing any performance, hours and hours of labor are saved by loose laying the entire roof system.
Another common application is in reroofing, especially in cases where mechanical attachments are not practical
or desired. Some examples would be where there are food prep areas or clean rooms that cannot be disturbed while in operation, and shutting down facilities to install new roofs is not something building owners typically want to pursue. Any time you are looking at installing a new roof over an existing roof and there is a compelling reason not to install thousands of fasteners through the roof deck. The existing roof system will act as an air barrier creating a sealed condition over any deck type.
You can also leverage the cost savings provided by using V2T to upgrade the roof system. Better or thicker membranes, more insulation, and incorporating high-performance coverboards are just some ways to maximize the dollars spent on roofing projects.
Another common advantage is convenience. By utilizing V2T when roofing an occupied building, you will greatly
reduce the noise generated by installing a new roof. You will also eliminate nearly all odors from adhesives and solvents because there are very few adhesives needed. Using V2T will also shorten the duration of installation, meaning business in an occupied space can get back to normal much faster. All these factors work to minimize the impact to whomever occupies the building. From hotels and retail facilities, to offices and schools, minimizing disruptions to the occupants should be an important factor when deciding which roof system to
install.
Consider the following types of installations in which this benefit is of strong importance:
■ Food prep or manufacturing facilities that must avoid penetration of the deck and limit the use of adhesives.
■ Hospitals, schools, child care facilities, doctors' offices, or anywhere else that the smell of adhesives may
cause alarm.
■ Properties near residential areas in which homeowners might complain about adhesive odors or noisy
construction occurring next door.
Above all, the greatest benefit that the V2T system provides is the peace of mind that comes with knowing this
revolutionary vent system has been proven to deliver reliable results in rain, snow, heat, cold, and even hurricane conditions. Remember, the harder the wind blows, the stronger the V2T system works to protect the roof.
David Harrison has over 30 years of experience in nearly all areas of the low-slope roofing industry and has gained in-depth technical knowledge of low slope roof systems and accessories by working for contractors, manufacturers, consulting and architectural/engineering firms. He attended the University of Tulsa studying engineering, business, and education. David and his wife, Anne, live in Wytheville, Virginia and enjoy watching the adventures of their two grown children, Thomas and Elise. In his spare time, David officiates soccer and tennis and has had the unique opportunity of calling lines for the likes of John McEnroe, Pete Sampras, and the Williams sisters. Jeremiah "Jeremi" Robinson holds a B.S. degree in mechanical engineering from West Virginia University. His unique combination of experience, skill, education and knowledge makes him a valuable addition to the V2T team. Robinson is passionate about the roofing industry and enjoys working with people and building relationships. He also enjoys the fact that V2T is a very technical system, and with his engineering background he has the opportunity to apply engineering principals to the industry. Jeremi especially likes the challenge of explaining the unique physics principals utilized by the V2T system in ways that make sense to people who aren't engineers. You can contact V2T at 704-800-3585.
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