If you’ve done some research on how hurricanes destroy homes, odds are that you’ve seen the term “sudden pressurization” thrown around in a few science-focused articles. But what does sudden pressurization mean in the context of a hurricane and exactly how does it destroy a home?
Let’s talk about what the term means, how pressurization of your home’s internal structure affects it during a hurricane, and what you can do to safeguard your home.
What Is Sudden Pressurization?
Simply put, sudden pressurization is a term for when hurricane-force winds are able to breach the envelope of the home and act directly on the internal portion of the structure.
When a window is left open or breaks during a storm, external air can rush into the gap. This causes the air inside the home to overpressurize. The stronger the wind, the greater the pressure exerted.
On a normal ‘windy’ day, where gusts are at 25 mph or less, this isn’t a problem. However, during a hurricane, an open or broken window suddenly becomes a huge problem.
How Sudden Pressurization Affects the Interior of Your Home
At sea level, air density is typically around 0.0765 pounds per cubic foot (Source: Omni Calculator). This can change depending on factors like temperature and elevation, but since Florida of only six meters (or about 19.68 feet) above sea level. Britton Hill in Walton County being the highest point at 345 feet above sea level (Source: Topographic Map), assuming an air density at sea level should work for most homes. Especially for those homes near the coastline, which are most in need of hurricane protection.
The average bedroom is roughtly 14’ by 16’, or 224 square feet. With a ceiling height of between 8’ to 10’ depending on construction date (new homes tend to have higher ceilings.
When wind enters the average bedroom, that means that there’s anywhere from 1,792 to 2,240 cubic feet of space to fill. There’s also 480 square feet of wall (two 14’ walls and two 16’ walls, each 8’ high) and 224 square feet of ceiling (and another 224 feet of flooring) to press against. That’s a total of 704 square feet of surface area now being exposed to direct pressure from the wind (excluding the floor).
A 65 mph wind acting on that amount of total surface area would exert a total force equal to 7,607 pounds, according to a wind load calculator. That’s a lot, but not catastrophic for most well-built homes on its own.
However, at 165 mph, or the wind speed of a Cat 5 hurricane, that load jumps to 49,015 pounds of force acting on the interior walls and the underside of your ceiling.
That’s roughly 24.5 tons of force. It’s like having a dump truck sitting on the internal structure of your home. A fully-loaded one, no less. No residential home is rated to survive that kind of pressure.
It only takes a single failed window for all that force to start acting on your home’s internal walls. And, the larger the room that the failed window connects to, the worse the damage will be. That’s because there will be more surface area for the high-speed winds to press against.
Big window openings are more likely to be struck by flying debris in a storm than smaller ones, increasing the risk of breakage. Also, the bigger the window, the more air can flow into the home if it breaks.
What’s the effect of all this pressure?
This level of internal pressure, combined with the stress of the ongoing windward (positive) and leeward (negative) pressure acting on your home can lead to sudden catastrophic structural failure.
Your roof can be blown off your home. Your interior walls can collapse under the weight of the weight of all that wind. Even if the walls and ceiling don’t fail outright, the wind can cause stress to your home’s interior, weakening it in ways that aren’t readily visible and making your home more vulnerable to unexpected structural failures in the future.
This isn’t even taking into consideration the potential for water damage to your property following a window breach during a storm. Standing water, especially dirty storm surge water, can carry all kinds of pathogens into your home, promote mold growth, and cause severe damage to furniture and electronics.
What Can You Do to Protect Your Home from Sudden Pressurization in a Hurricane?
So, what can you do about sudden pressurization that collapses the interior walls and blows out the roof of your home? The best strategy is to prevent the wind from getting inside your home in the first place.
There are several ways to accomplish this, such as:
Boarding Up Windows
A basic short-term strategy, boarding up your window openings can protect window glass from direct debris impacts and the pressure caused by oncoming wind.
However, this is not an ideal solution because:
- The protection is temporary.
- Boards can be torn away from the opening by extreme winds.
- It’s a lot of manual labor to carry out for every storm, especially if you have a multistory home.
- Cheaper boards tend to only be good for a single storm, while higher-quality boards require a lot of storage space.
- Improperly-installed boards may not completely protect the window from wind pressure.
Despite these flaws, boarding up windows is a better alternative than doing nothing to protect your vulnerable window openings. This remains a useful last resort for homes that don’t have more permanent forms of wind mitigation protection for their window openings.
Using Shutters to Cover Windows
A better, longer-term solution than boarding up windows, huricane shutters are devices that are externally installed over (or around) your window openings that can be shut to provide protection during a storm.
Shutters come in many varieties, from the old-fashioned hinged slabs of wood installed over a window to more modern steel shutters which can be rolled down or over a window opening to provide durable protection against the wind.
While better than boarding up windows, there are a few issues with shutters:
- They absolutely impact the curb appeal of your home in a negative way.
- They still need to be manually deployed in the event of a storm (but it’s much easier than nailing up boards of plywood or plastic).
- When deployed, they block all visibility, so they aren’t useful for daily protection.
- Metal shutters can be highly susceptible to rust from exposure to salty ocean breezes, meaning they require semi-frequent replacement.
All in all, hurricane shutters are a mediocre solution to the problem of hurricane-force winds and flying storm debris. But they are leagues better than nailing up the side of your house.
Replacing Windows with Impact Windows
The best, longest-lasting solution is to replace fragile non-impact windows with impact-rated models designed to withstand the harshest wind, rain, and flying debris impacts possible.
Impact window replacement is a comprehensive solution that massively reduces the risk of a catastrophic window breach without negatively impacting your home’s curb appeal.
The best part? Full-on window replacement provides 24/7 protection from more than just hurricane-force winds. It’s security against would-be break-in artists, as well! With impact-rated laminated safety glass, an impact window can hold back a home invader for much longer than a typical window.
The only downsides are that it costs more and takes longer to complete than simply boarding up windows.
How Long Does Impact Window Replacement Take?
The actual installation of a new impact window doesn’t take long in and of itself. Once a window is onsite, it generally takes between two and four hours to rip the old window out and put the new one in.
Rather, the source of the wait is that each impact window needs to be custom made for your home’s window openings.
Even if your home uses ‘standard’ window opening sizes, issues like the structure’s frame settling can alter your window opening sizes. So, each window opening needs to be measured first, and the window is then made-to-order for that specific opening. This practice helps to ensure a tight, secure fit so the window can be anchored properly to your home.
Additionally, you may want to take the opportunity to make some seamless upgrades to your windows. Optional upgrades like argon gas fills, low-e coatings, and tints can help enhance your windows’ energy efficiency or make the window more attractive to increase curb appeal for your home.
Get Expertly-Installed Impact Windows to Protect Your Home from Sudden Pressurization
Want to get beautiful new windows that can protect your home from the worst effects of hurricanes? Reach out to Karoly Windows & Doors today to get:
- A FREE in-home window assessment.
- Professional consultation with top window recommendations.
- Exclusive discount offers on whole-home impact window replacement.
- Real expert installation service from a team of in-house professionals who specialize in impact window installation.
- Window financing that makes new window installation easier to fit into nearly any budget.
With Karoly, you always get top-notch installation service from a real expert, never a subcontractor.
Expert installation can really make a massive difference in how well your new windows protect your home. Get the best installation possible!
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