Defining Design Pressure & the Ratings for Openings

What does a Design Pressure (DP) rating actually tell you—and how do you know whether a window, door, garage door, or other opening is rated appropriately for a FORTIFIED Home™?

In this episode of The FORTIFIED Factor, our AI Experts (informed by Knockout Inspections) break down one of the more technical—but incredibly important—concepts in resilient construction: required design pressure versus a product’s design pressure rating.

Required design pressure represents the wind pressure a component of the home must be capable of resisting. That pressure isn't necessarily the same everywhere on a structure. Factors such as design wind speed, exposure category, building height, location on the building, and other site and building characteristics can affect the pressures a component must withstand.

A DP rating, on the other hand, represents the pressure a particular product or system has been tested and rated to resist. The key is matching the two: the product's documented capacity must meet or exceed the pressure required at its specific location on the home.

We'll discuss why simply seeing a DP number on a product isn't enough, why documentation and tested assemblies matter, and how installation can ultimately determine whether a rated system performs as intended.

The same principle highlighted in FORTIFIED guidance for roof coverings is essential to understanding design pressures throughout a resilient home: determine the required pressure, verify the tested rating, and install the system according to its approved requirements.

Whether you're a homeowner trying to understand FORTIFIED requirements, a contractor selecting products, or an industry professional working toward a FORTIFIED designation, this episode will help make the numbers behind wind resistance easier to understand.

Have questions about design pressures, opening protection, or the FORTIFIED Home™ program? Contact the team of in-house FORTIFIED Evaluators at Knockout Inspections at 855-GO-FOR-KO (855-463-6756) or visit fortifiedhome.com.