Rooftop Equipment Hurricane Protection

Tie Down the AC: Hurricane Anchoring

Vibration isolators let the AC run smooth. But they do not hold it down during a hurricane. Click the button to see what happens to rooftop equipment with and without hurricane straps.

Without Hurricane Straps

5-TON RTU

Unit slides off roof

With Hurricane Straps

5-TON RTU

Unit stays anchored

Calculate Equipment Loads Restraint Types

Hurricane Restraint Options

Different ways to keep equipment on the roof during 180 mph winds.

Cable Restraints

Steel cables with turnbuckles connect equipment to roof curb. Allow vibration isolation while limiting lateral movement.

Snubber Brackets

Metal brackets with rubber bumpers. Equipment floats normally but contacts snubbers during high wind or seismic events.

Direct Anchor

Equipment bolted directly to curb without isolators. Highest restraint but transmits more vibration to building.

HVAC Anchoring Checklist

Make sure your rooftop equipment is ready for hurricane season.

Calculate Wind Forces

Determine uplift, overturning, and sliding forces based on equipment size, weight, and roof location.

Select Restraint System

Choose cable restraints, snubbers, or direct anchoring based on vibration isolation needs and wind forces.

Verify Curb Connection

Ensure equipment curb is properly anchored to roof structure with capacity to resist wind loads.

Install to Manufacturer Specs

Follow restraint manufacturer installation details including torque values and cable tension.

Inspect Annually

Check restraints before hurricane season for corrosion, loose connections, or damaged components.

HVAC Anchoring FAQs

Common questions about rooftop equipment restraints

How do you anchor rooftop HVAC equipment for hurricanes?

Rooftop HVAC equipment requires seismic/wind restraints in addition to normal vibration isolators. Hurricane straps or cables connect the equipment frame to structural curbs or roof steel. Connections must resist uplift, overturning, and sliding forces. In Miami-Dade HVHZ with 180 mph winds, a typical 5-ton rooftop unit might need 4 anchor points rated for 1,500+ lbs each.

Can vibration isolators resist hurricane wind loads?

No. Standard vibration isolators (spring isolators, rubber pads) are designed to reduce vibration transmission, not resist lateral or uplift forces. During hurricanes, equipment on isolators alone will slide, tip over, or blow off the roof entirely. Hurricane restraints work WITH isolators - restraint cables or snubbers allow normal vibration isolation while limiting movement during high winds.

What wind loads affect rooftop equipment?

Rooftop equipment experiences three wind force components: Horizontal drag (wind pushing sideways), Uplift (low pressure trying to lift equipment up), and Overturning (combination that tries to tip equipment over). The design must resist all three. Equipment near roof edges and corners sees higher loads than equipment in the middle of the roof.

Do existing HVAC units need to be retrofitted?

If existing rooftop equipment lacks hurricane restraints, it should be retrofitted - especially in Miami-Dade HVHZ. Many pre-1990s installations used only vibration isolators. Retrofit kits with cable restraints can usually be added without removing the equipment. The cost of restraints ($500-2000 per unit) is far less than replacing equipment that blows off during a hurricane.