Nigh 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 time? Florida has a notoriously unpredictable climate. Loftier winds and inclement weather can whip up at any given fourth dimension. So the question remains, how much wind can a window withstand? For example, can seventy mph winds break windows?

What risks do high winds pose to windows?

Hurricanes aren't the but windy weather condition events that Due south Florida faces. Afternoon rainstorms or even tropical disturbances hundreds of miles away tin can cause gusts or sustained high winds. According to the National Weather Service, a wind gust is a sudden, brief increase in wind speed that peak at to the lowest degree 18 miles per hour and have lulls that vary by at least 10 miles per hour. A gust normally lasts less than twenty seconds. Fifty-fifty though Hurricane Dorian recently missed the Florida coastline, tropical storm-force winds were still felt in Miami-Dade and Palm Beach Counties.

When windows neglect during a hurricane, broken glass, droppings, and huge amounts of water enter the home, causing catastrophic damage, or worse, injuries or decease. Older windows are specially at risk as they may not be properly mounted or framed. A 50 mph current of air will employ five to vii pounds of force per square foot, but this increases exponentially as winds get stronger. At 100 mph, that figure jumps from xx to 28 pounds of pressure level per square foot, and at 130 mph, 34 to 47 pounds per square foot of pressure are applied.

How strong does wind have to be to interruption windows?

Hurricane air current speeds start at 74 mph, but here'south the impairment that winds tin can do earlier and up to that bespeak, according to the National Severe Storms Laboratory:

  • 19 mph: small copse begin to sway
  • 25 mph: umbrella use becomes difficult, whistling tin can be heard through wires and branches
  • 32 mph: whole trees sway and walking into the wind becomes difficult
  • 39 mph: branches can be broken from trees, cars can veer on the route
  • 47 mph: light structural damage
  • 55 mph: trees can be uprooted, considerable structural harm is possible
  • 64 mph and upward: widespread structural impairment is possible

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

Category 1: 74-95 mph

Winds at this speed will generally cause damage to mobile homes and copse, only well-synthetic frame homes may see minor damage to the roof or gutters. Shallowly rooted trees may topple and impairment to power lines can cause ability outages that last for days. A storm surge of 4-v feet above normal tin cause coastal road flooding.

Category ii: 96-110 mph

These winds are extremely dangerous; homes may sustain roof, siding, window and door damage. Trees volition sustain considerable impairment 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 afterward the storm passes, major copse are snapped or uprooted, homes may incur major damage.

Category 4: 130-156 mph

Catastrophic damage; homes can suffer severe impairment including the loss of the roof structure, windows, doors and/or some outside walls. Most of the expanse will be uninhabitable for weeks or months. The storm surge is more often than not thirteen to xviii anxiety above normal levels. Land that is less than 10 feet in a higher place sea level may be flooded.

Category 5: 157 mph or college

These storms destroy almost homes, causing roof failure and wall collapse. The storm surge is usually more xviii feet higher than normal. Fallen trees and power lines will isolate areas, with many shrubs, trees, and signs diddled down. Lower levels of all structures sustain major damage and there are massive evacuations of residential areas. Power outages tin terminal for weeks or months, and nearly of the area will be uninhabitable.

And so with all that said, at what current of air speed do windows break? A Design Pressure level or DP rating measures the strength of a window. Standard residential windows take DP values between xv and 50. A DP 15 window can reasonably be expected to sustain winds of roughly 77 mph earlier shattering.

 A DP 50 window is expected to sustain winds up to 173 mph. The windows installed in your habitation will depend on what the building code dictated at the fourth dimension of installation. Afterwards Hurricane Andrew, Miami-Dade has one of the strictest building codes in the country. Note that dissimilar impact glass, these values only business relationship for wind speed, not projectiles.

What to do if a window breaks during a hurricane

If you lot aren't required to evacuate and decide to ride out the hurricane, be certain to have all the necessary precautions beforehand. This includes making sure to secure and caryatid external windows and doors, remove projectiles, trim bushes, and shrubs. Then stock upwards on supplies such as water, nutrient, and batteries, and heed to a bombardment-operated radio or television for storm updates.

Practice non tape windows in an try to prevent shattering, and never, ever leave the windows slightly open up to effort to stabilize the force per unit area. Taping windows does not make them more shatter-resistant, it merely ensures that larger pieces of shattered glass are flying effectually in a storm. Inviting a violent air current into your home by way of open up windows will destroy the structure from the within.

If a window breaks during a hurricane and y'all are home, immediately move to a room with few or no windows, if you aren't in that location already. Be sure to close the doors to the rooms with broken windows when you leave, and don't try to make whatsoever repairs until the winds die down. You lot may exist able to make a quick set up while the eye of the tempest passes, but be sure that someone else in the firm is standing by to warning you lot when the winds start picking up once more. After the storm passes, article of clothing gloves while cleaning up and be sure to document for your insurance company.

Other threats to windows

In addition to shattering the drinking glass, winds tin can devastate homes when windows fail past destabilizing the pressure and causing walls or roofs to collapse. Additionally, blown-over copse and signs become projectiles in hurricane-force winds, so considering installing impact glass is a adept idea. Plus, affect glass has the added benefits of better insulation and added protection against break-ins.

Body of water Impact's country of the art bear on windows are missile-tested for forcefulness and designed to withstand winds of up to 175 mph. If you're non sure if your windows are ready for the next hurricane, tropical storm or windy 24-hour interval, contact us today for an approximate.