You may have seen windstorm classification ratings like as 1-60, 1-90 or 1-120. Building owners and sometimes even uninformed contractors too often correlate these classification ratings to wind speeds of 60, 90 or 120 miles per hour (mph). Yet, they’re incorrect! When you see a windstorm classification rating, it’s actually talking about wind uplift pressures in pounds per square foot (psf). See, it’s not talking about wind speeds. So, a roofing system rated as some may say, “120” doesn’t mean that it will hold up in a rainstorm with 120 mph winds. Unfortunately, it’s way more complicated.
ASCE standards tell us how to calculate wind uplift pressures. Most building codes rely on their advice.
Wind Uplift Pressures For Windstorm Classification Ratings
So, there’s no way to determine a rating needed using basic wind speed only. That’s just one factor out of the five basic factors usually considered. State or local rules usually say what calculation they require for determining the windstorm classification ratings needed on any particular building. However, all formulas consider five basic factors:
- building height
- building location
- surrounding terrain
- building openings
- building use
Together in a formula, these factors shows pressure in pounds per square foot that the building may face. Then, builders know what rating they may need. Do you know the windstorm classification rating you need for your building?
Endureed synthetic thatch is wind rated and can tolerate extreme winds. Our products have survived Category 5 hurricanes and tornadoes.
CONTACT ENDUREED FOR A CONSULTATION
Whether you’re interested in roofing an indoor gazebo or an entire hotel, we’d love to help you choose the right product for the job.
Check out our synthetic thatch roofing materials now to find one that’s right for you:
- Capetown– A trimmed, coarsely textured, longer reed. Replicates African Yellow Grass or “Cape Reed” that replicates the typical African style thatching.
- Kilimanjaro– A heavy reed replicating a traditional weathered, Tanzanian cape reed roof.
- Somerset– A closely tapered, slightly weathered appearing shingle. Replicates a typical, hand trimmed European thatching.
- Kona– A combination of wide leaf and smaller grass reed. Replicates the look of Hawaiian “Pili Grass” and Asian Alang-Alang grass thatching.
- Dominica– A synthetic palm leaf style thatching. Replicates palm leaves commonly used in tropical regions throughout the world.
- Bali– A finer, loosely tapered, slightly longer shingle designed to resemble the appearance of East Asian grass thatching.
- Viva Series– An especially economical synthetic palm thatch.