Wind Uplift On Roofs

To ensure a correctly built metal roof there are a variety of wind uplift tests manufacturers use to test their metal panel systems.

Wind uplift on roofs.

Thus for the structure s design along with other loads wind load must also be considered. It is also used to calculate wind uplift pressures on a roof and the changes to the basic wind speed maps better reflect regional variation of wind speeds across the country. Design and performance requirements. The uplift loads acting on a roof are influenced by a number of factors geographic location the local building code dimensions exposure use and occupancy aka risk factor and type.

Roof damage caused by wind occurs when the air pressure below the roofing assembly is greater than the air pressure above the building s roof. When building a structure it is important to calculate wind load to ensure that the structure can withstand high winds especially if the building is located in an area known for inclement weather. Keep in mind that the roofing system includes the surface materials and the fasteners used to attach them to the roof deck. Specific metal roof products panel profiles and applications that perform best for wind uplift.

Wind uplift is created when the air pressure below the roofing system is higher than the air pressure above the roof. Methods and accessories to improve wind uplift characteristics for metal roofs. Whenever the wind blows over a roof s surface the air pressure directly above the roof decreases. Wind uplift ratings wind zones and specific wind uplift requirements.

In order for a structure to be sound and secure the foundation roof and walls must be strong and wind resistant. At the same time internal air pressure increases due to air infiltration through openings cracks etc. Current wind uplift tests and how they are performed. In a study of wind load on roof tiles the vulnerability analysis indicated that the net wind uplift loading on tiles caused an increase in tile destruction rather than the external surface pressures li et al.

As it is redirected it increases its velocity and creates uplift. The result is a net upward force on the roofing system. Wind uplift when a gust of wind encounters a structure by nature it is redirected up the structure s face and across the top plane of the structure roof as it continues its journey. The purpose of this test is to gain uplift resistance data for the panel assembly and evaluate the attachment of the roof covering systems to the roof decks.

The ul 1897 wind test is a continuation of ul 580 and is the standard for uplift tests for roof covering systems. Roofs need to resist the uplift loads acting on the roof. Many institutes have been performing wind tunnel tests on green roofs and canada is the first country to employ a standard method for testing wind uplift on vegetated roofs.