Most South Florida homeowners understand the importance of securing windows earlier an impending hurricane. Fifty-fifty though hurricane conditions are well known in advance, what about the rest of the fourth dimension? Florida has a notoriously unpredictable climate. High winds and inclement weather can whip up at whatever given time. So the question remains, how much wind can a window withstand? For example, can 70 mph winds break windows?

What risks exercise high winds pose to windows?

Hurricanes aren't the only windy conditions events that South Florida faces. Afternoon rainstorms or fifty-fifty tropical disturbances hundreds of miles away tin crusade gusts or sustained high winds. Co-ordinate to the National Weather Service, a air current gust is a sudden, brief increase in wind speed that elevation at least xviii miles per hr and have lulls that vary by at least 10 miles per 60 minutes. A gust commonly lasts less than 20 seconds. Fifty-fifty though Hurricane Dorian recently missed the Florida coastline, tropical tempest-force winds were still felt in Miami-Dade and Palm Beach Counties.

When windows fail during a hurricane, broken glass, droppings, and huge amounts of water enter the home, causing catastrophic damage, or worse, injuries or death. Older windows are especially at risk as they may not be properly mounted or framed. A 50 mph air current will utilize v to 7 pounds of force per square foot, simply this increases exponentially as winds get stronger. At 100 mph, that figure jumps from 20 to 28 pounds of force per unit area per foursquare foot, and at 130 mph, 34 to 47 pounds per square pes of pressure are applied.

How strong does wind have to be to interruption windows?

Hurricane current of air speeds starting time at 74 mph, but here'southward the impairment that winds can do before and upward to that bespeak, according to the National Severe Storms Laboratory:

  • nineteen mph: small trees begin to sway
  • 25 mph: umbrella use becomes difficult, whistling can be heard through wires and branches
  • 32 mph: whole copse sway and walking into the wind becomes hard
  • 39 mph: branches tin can exist broken from copse, cars can veer on the road
  • 47 mph: low-cal structural damage
  • 55 mph: copse can be uprooted, considerable structural damage is possible
  • 64 mph and upwards: widespread structural harm is possible

According to the Saffir–Simpson hurricane wind calibration (SSHWS) , tropical tempest-force winds begin at 39 mph. The SSHWS is the well-known scale that classifies hurricanes into five categories based on wind speed:

Category one: 74-95 mph

Winds at this speed will mostly crusade damage to mobile homes and trees, merely well-constructed frame homes may see minor damage to the roof or gutters. Shallowly rooted trees may topple and harm to power lines tin cause power outages that last for days. A storm surge of 4-5 anxiety in a higher place normal can cause coastal road flooding.

Category 2: 96-110 mph

These winds are extremely dangerous; homes may sustain roof, siding, window and door impairment. Trees will sustain considerable damage and some are uprooted, blocking roads. The storm surge is usually 6 to 8 feet above normal. Coastal and low-lying areas are evacuated.

Category 3: 111-129 mph

Mobile homes and poorly constructed buildings are destroyed. The storm surge is typically 9 – 12 anxiety higher than normal. Electricity and water may be unavailable for days to weeks after the storm passes, major trees are snapped or uprooted, homes may incur major damage.

Category four: 130-156 mph

Catastrophic damage; homes can suffer severe damage including the loss of the roof structure, windows, doors and/or some exterior walls. Nigh of the area will be uninhabitable for weeks or months. The storm surge is mostly 13 to 18 feet above normal levels. Land that is less than x feet above sea level may exist flooded.

Category 5: 157 mph or higher

These storms destroy most homes, causing roof failure and wall plummet. The tempest surge is ordinarily more than than eighteen feet college than normal. Fallen trees and power lines will isolate areas, with many shrubs, trees, and signs blown downward. Lower levels of all structures sustain major impairment and there are massive evacuations of residential areas. Power outages can last for weeks or months, and near of the expanse volition be uninhabitable.

Then with all that said, at what wind speed practice windows interruption? A Design Pressure or DP rating measures the strength of a window. Standard residential windows have DP values between 15 and 50. A DP xv window tin reasonably be expected to sustain winds of roughly 77 mph before shattering.

 A DP 50 window is expected to sustain winds up to 173 mph. The windows installed in your home will depend on what the building code dictated at the time of installation. After Hurricane Andrew, Miami-Dade has one of the strictest building codes in the country. Note that unlike impact glass, these values only account for air current speed, not projectiles.

What to do if a window breaks during a hurricane

If you lot aren't required to evacuate and make up one's mind to ride out the hurricane, be sure to take all the necessary precautions beforehand. This includes making certain to secure and brace external windows and doors, remove projectiles, trim bushes, and shrubs. Then stock up on supplies such as water, food, and batteries, and listen to a battery-operated radio or telly for storm updates.

Practise not tape windows in an effort to prevent shattering, and never, ever get out the windows slightly open up to endeavor to stabilize the pressure. Taping windows does non make them more than shatter-resistant, it just ensures that larger pieces of shattered glass are flying effectually in a storm. Inviting a trigger-happy current of air into your home by style of open windows will destroy the structure from the inside.

If a window breaks during a hurricane and y'all are domicile, immediately motion to a room with few or no windows, if yous aren't there already. Be certain to close the doors to the rooms with broken windows when yous go out, and don't try to make any repairs until the winds die downward. Y'all may be able to make a quick set up while the centre of the tempest passes, just be sure that someone else in the house is standing by to alarm you when the winds first picking upwards again. Later the storm passes, wearable gloves while cleaning up and be sure to certificate for your insurance company.

Other threats to windows

In improver to shattering the glass, winds tin can devastate homes when windows neglect past destabilizing the pressure and causing walls or roofs to collapse. Additionally, blown-over copse and signs get projectiles in hurricane-forcefulness winds, then because installing impact glass is a skillful idea. Plus, impact glass has the added benefits of amend insulation and added protection against break-ins.

Ocean Impact'southward country of the art impact windows are missile-tested for strength and designed to withstand winds of upwards to 175 mph. If you're non certain if your windows are set for the next hurricane, tropical storm or windy twenty-four hour period, contact us today for an gauge.