There is a common misconception that leaving doors or windows ajar during a storm will create ventilation and reduce air pressure, thus preventing roof damage or broken windows. However, this is not true, and doing so can actually cause more harm than good.
So, should you open doors and windows during a storm? The answer is no. Opening doors and windows during heavy rain and strong winds will not reduce air pressure but may lead to more severe consequences.
According to the McGill University Office for Science and Society (Canada), if our house were an open box with large openings on both the windward and leeward sides, most of the wind would pass through, reducing the pressure on the structure. However, our homes are not open boxes. They have internal doors, closets, furniture, and other obstacles that prevent the wind from passing straight through and cause it to hit walls and other objects inside.
Leaving doors and windows ajar can invite strong winds into your home, causing significant damage and posing risks to your safety. The force of the wind can lift and throw objects, such as outdoor furniture, glass panes, roofing sheets, or tiles, which may then break or cause harm if they enter your home.
Therefore, it is crucial to keep all doors and windows firmly shut to prevent debris and broken pieces from entering your home.
The Institute for Business & Home Safety (IBHS) in the United States recommends closing all interior doors (including the main entrance and windows) to divide the pressure into smaller areas, thus reducing the overall pressure on the roof.
Instead of leaving doors and windows ajar, secure them tightly and consider using sandbags or heavy objects to reinforce them, minimizing the impact of the storm.