Wind damage

Factory Mutual provides loss prevention data sheets that explain how to protect buildings from wind damage. Pressure coefficients that define increased uplift at corners and edges adjust the calculated uplift pressures. A laboratory uplift pressure test rates roofing assemblies. An uplift pressure of 2.9 kPa (0.42 psi) must be withstood under FM conditions to meet the Class 1-60 requirements. The FM approval guide is revised aimuaHy (37). 

An enclosure is usually an air-supported structure which permits the collection and treatment of gaseous wastes produced by surface impoundments. Enclosures are susceptible to wind damage and can be harmed by the wastes they cover. Subject to these limitations, control effectiveness approaches 100 percent (University of Arkansas and Louisiana State University, 1985). 

The tops of Jerusalem artichoke can also be cut off at 1.5 m to reduce the likelihood of wind damage (Wood, 1979), which in this instance prevented the plants from flowering. Wind also affects leaf temperature and the rates of photosynthesis and transpiration, with resulting but minor effects on growth rate (Meyer et al., 1973). 

Peonies prefer full sun and moist, well-drained, richly organic soil, although light shade is tolerated and may prolong bloom in the South. A protected site limits wind damage to blossoms. Most are hardy to Zone 5 and do best in cold-winter climates. 

Tornadoes are considered nature s most violent storm and are associated with the occurrence of severe thunderstorms and hurricanes. As opposed to a hurricane, where damage is possible over a wide geographic area, a tornado causes localized damage due to direct contact between objects and the swirling vortex. When a tornado comes in direct contact with a building, the usual result is total destruction due to wind damage. 

The biological energy necessary to resist wind damage would otherwise be spent on growth and reproduction. Plants that withstand the pressure of wind are often stunted and without many offspring. 

Community emergency management organizations have improved cleanup and salvage operations for tornado and wind damage to their communities. It is not uncommon for many volunteers to show up and help clean up the destruction. Someone needs to coordinate their activities. 

Resins are solid, brittle substances secreted by plants into special ducts, often as a response to damage to the plant by wounding, wind damage, etc. Their main role appears to be protection of the plant from attack by fungi and insects. Resins are difficult to classify because of their amorphous nature they are complex mixtures that include lignans, resin acids, resin alcohols, resinotannols, esters and resenes (see Table 7.3). 

Amongst the synthetic growth retardants chlormequat chloride (2-chloro-ethyltrimethylammonium chloride), introduced by Cyanamid in 1959, has several uses including reducing the height of cereals to minimize wind damage and facilitate mechanical harvesting. 

Zeng, H., Talkkari, A., Peltola, H KeUomaki, S., 2007. A GIS-based decision support system for risk assessment of wind damage in forest management. Environmental Modelling Software, 229 1240-1249. Elsevier, New York. 

Roofing materials are exposed to harsh conditions, which cause degradation in properties over time. Deterioration occurs due to wind damage, sunlight exposure, rain, snow, hail, and temperature variations [20]. To prevent, or at least slow down these processes, thermal and UV stabilizers, antioxidant materials, and flame retardants are added to the plastic in appropriate amounts. PVC membranes also contain plasticizers for flexibility. 

---