Wind is the design load
A tensioned sail acts like, well, a sail. Wind adds load on top of the tension already in the fabric, and that load goes straight into the corners, posts and footings. Breathable HDPE lets some air pass through, which helps, but posts and anchors still have to be designed for real gusts. Our notes for engineers cover dynamic loading and fabric properties.
Arizona monsoons
Monsoon storms from roughly mid-June through September bring sudden outflow winds; the National Weather Service regularly warns of gusts of 60 mph or more in severe storms. Two sensible approaches:
- Engineered structures — posts, footings and hardware designed for your site’s code wind speed so the sail can stay up.
- Residential sails on lighter anchors — quick-release hardware so the sail comes down before a severe storm (a good rule of thumb: forecast winds over about 50 mph).
When you need engineering
Commercial projects, public spaces, playgrounds, larger residential sails and anything on new posts benefit from structural engineering to the building code (ASCE 7 wind loads, as adopted by your jurisdiction). Engineering sizes the posts, footings and connections — and is usually what the permit office wants to see.
What the building code says
Most states build on the International Building Code (IBC); the 2021 edition is the one in effect in the most states, and section numbers here are from it. Phoenix adopted the 2024 codes effective August 1, 2025, so always confirm the edition with your building department. Depending on how the city classifies a shade structure, two sections usually apply:
- IBC 3102, membrane structures (in place 180 days or longer): tensile membrane structures are designed to ASCE 55; the membrane must be noncombustible or pass NFPA 701 flame propagation; and the structure is designed for dead, tension, wind and other loads under Chapter 16. The membrane can’t be counted on to brace the frame.
- IBC 3105, awnings and canopies: designed for wind and live loads under Chapter 16, with allowance for open construction; the covering must pass NFPA 701 or have a flame spread index of 25 or less under ASTM E84. Commercial 95 is rated ASTM E84 Class A (flame spread 0–25), and fire-retardant versions are available where NFPA 701 is required.
- Wind comes from ASCE 7, as referenced by IBC Chapter 16, using your site’s wind speed, exposure and risk category.
Architects can download our three-part guide specification (Section 13 31 23) for tensioned fabric shade structures. See also our notes for engineers.
Permits in the Valley
Requirements vary by city and by project, so always check with your local building department. In general:
- Permanent structures on concrete footings — especially commercial, public and larger residential structures — commonly require a building permit.
- Setbacks, lot coverage and height limits may apply.
- HOAs frequently require architectural approval regardless of the city’s rules.
We don’t do permitting or approvals — those are the property owner’s responsibility, working with a third-party structural engineer who provides any stamped plans or calculations. We’ll assess your site, make a recommendation, and build to the engineer’s plans.