Design Pressure

Design Pressure (DP or Structural Load) Rated Doors

    In August of 1992, Hurricane Andrew blew through Florida causing approximately $30 billion in damage.  As a result, the Florida Building Code was revamped, creating new building requirements for many product categories, including doors. 

    Design Pressure (DP), or structural load, is aimed at preventing significant pressurization of a structure’s interior by setting a minimum wind load standard.  The higher the DP requirement for the door system, the higher the velocity of wind the system must be able to resist.

    Design Pressure is generally expressed in two numbers, one positive and the other negative.  The positive number is the standard for wind blowing at the structure, and the negative number is for the vacuum pressure on the interior of the structure.  To test a door system for DP, technicians put the system through a cycle that includes both positive and negative air pressure. 

    Design Pressure requirements are site specific and can vary significantly depending on the location of the structure.  For example, a two story home built in a 100 mph wind zone of Central Florida might require a design pressure rating of +24/-27 psf.  That same home built in Broward County would require +53/-58 psf, while +58/-63 psf would be required for Dade County. 

    While those rough guidelines may apply in most situations, DP requirements must be determined by a local architect or engineer and are specific to each structure.  Factors to be considered include the location of the building (i.e. wind speed zone, the overall height and type of structure, and whether the building stands alone or in a development with other buildings).  DP requirements also vary depending on the location of the opening along a wall.  Because wind pressure is higher at the edges of buildings where it rushes to move around the structure, openings closer to the corner will have higher DP requirements than openings at the center of a wall.

    We have had most of our Panel and French door styles tested and have received approval for most areas within the state of Florida (FL# ).  Please contact your salesman for additional information and availability.