They are called impact windows because they are impact-resistant, not impact-proof. The glass may crack when it's hit, but it will not break into pieces, or break away from the frame. This prevents any debris, wind, or rain from entering your home and causing further damage.
While impact windows aren't indestructible, they are very hard to break. To get through, a burglar would create a ruckus and likely be caught. Breaking through impact windows typically proves to be considerable work and energy, forcing burglars to move on.
Impact glass is designed to resist heavy blows, and for this reason, it has become the mainstay in windshields for cars, trucks, and busses and more recently houses windows. Just like a car windshield, however, it can break if hit hard enough.
Impact Windows Are Just for Looks
Ultimately, hurricane-resistant windows are capable of withstanding winds of up to 200 miles per hour. If flying debris does hit a window, the added protection will keep the glass from breaking up into large sharp pieces.
While no window, lock, light or security system is 100% burglar proof, impact resistant windows and doors make it much more difficult for intruders to gain entry into your home.
The biggest drawback of impact windows is their cost, which is why they are typically only used in high-risk areas. However, it is beneficial in the long run because they last much longer than other types of glass.
In plain terms, yes, impact glass can break. However, as these glass structures receive impact, the inner layer of PVB keeps the structure from breaking down—it keeps the window standing even though the glass shatters. There are varying types of impact glass.
Installing these windows significantly lowers your chances of major damage to your home. Hurricane impact windows have advanced to the point where they can withstand Category 5 wind conditions, and the debris that goes with it. So next time a hurricane hits your neighborhood, don't be caught unprotected.
How much force does it take to break a house window? Depending on the manufacturer, the force required to break tempered glass ranges from 20,000 to 24,000 PSI (or pounds per square inch).
Impact windows are oftentimes worth the money. Though they're typically more costly than standard windows, the impact options can reduce the price of your home insurance and help prevent costly home damages caused by storms.
You don't want to spoil anyone's fun by telling them not to play because you're worried about your windows. With impact windows, you can let them play and they can even keep playing after a ball hits your glass because it won't break.
Hurricane windows are treated with a laminate that prevents the glass from breaking but does not stop a bullet from passing through them. These windows are designed to protect against flying debris caused by hurricane winds. So, to answer your question, no, hurricane or impact windows aren't bulletproof.
Category 4 Hurricane
These winds can destroy a home's roof structure and exterior walls, topple most trees and power lines, and cause damage that will last for months. Category 4 hurricanes cause extreme harm to glass windows and doors for homes and businesses.
Aluminium windows are considered one of the most secure options available on the market. It is one of the most burglar resistant materials available because of its inherently strong properties despite its featherweight appearance. When discussing aluminium's durability, it's much stronger than most people realise.
A polycarbonate window is much more difficult to break through than a standard glass window. In fact, according to some estimates a polycarbonate window is over 200 times more resistant to impact!
They likely assume that any window or door that can stand up to a hurricane can stand up to an intruder trying to break into your home. But we know better: hurricane windows are not security windows (and they're not even close to ballistic windows).
Pressure cracks are less common and always seem to come out of nowhere. Most commonly seen in insulated glass, or double-paned windows, pressure cracks can be caused by drastic pressure system changes in the weather or when windows are installed at too high or too low of an elevation level.
Glass typically has a tensile strength of 7 megapascals (1,000 psi). However, the theoretical upper bound on its strength is orders of magnitude higher: 17 gigapascals (2,500,000 psi). This high value is due to the strong chemical Si–O bonds of silicon dioxide.
For many passenger cars, the recommended air pressure is 32 psi to 35 psi when the tires are cold. There is also a tire pressure number shown on the sidewall of the tire itself.
Impact windows use thick laminated glass and sturdy framing materials, which result in a decrease in external noise by as much as 40%. Their overall thickness ranges from 7/16” to 9/16”, as compared to typical single pane glass measuring an average of 1/8”.
Impact windows and hurricane windows are not the same thing
While the terms may be used interchangeably by some, impact windows and hurricane windows differ in some key ways, namely the level of resistance they offer. Hurricane windows offer less insulation and their primary function is to resist wind damage.
All PGT WinGuard® windows and doors are rated for Impact Zone 3 and Impact Zone 4 ratings and are tested to withstand winds over 150 miles per hour in accordance with the ASCE Wind Zone Map.
If you're in the room where the window broke, move to another part of the house. If one window breaks, more might as well. Move to an inner room that perhaps doesn't have windows, like a closet or bathroom or even a basement if you have one. The storm can rage in, but you'll be safer away from windows of any kind.
To get technical for a moment, impact-resistant windows usually blend laminated and tempered glass together with a substance like polyvinyl butyral (PVB), producing an incredibly safe and secure glass that's able to handle direct “attacks”.
Choose a corner
Make sure you smash the corner of the window. Whether you hit from the inside to save yourself, or from the outside to save another: by hitting the corner of the window it will break fastest. Preferably protect your hand a little: safety glass is still pretty sharp.