Understanding Ultimate And Nominal Design Pressures For Windows And Doors

A higher dp value indicates a window or door that can withstand more wind water and or structural load than a window with a lower dp.

Understanding ultimate and nominal design pressures for windows and doors. Let s start with the definition of design pressure. Dp ratings represent three performance elements structural load water resistance and air infiltration resistance. The water penetration resistance test pressure for r products is also 15 of dp. Design pressures are the amount of pressure put on the openings envelopes windows doors during a hurricane.

For testing required in sections r612 6 r612 7 and r612 8 design pressures determined from table r301 2 2 or asce 7 are permitted to be multiplied by 0 6. According to aama american architectural manufacturers association wdma window and door manufacturers association and the nafs north american fenestration standard design pressure dp is a rating that identifies the load. Note also that for skylights the structural design pressure is 200 percent of design pressure whereas it is 150 percent for windows and doors. Understanding design pressures are relatively simple.

10 psf asd general requirements. Combined together all these factors give a measure of design pressure which is the product of all these different pressures a building is exposed to. Windows and sliding glass doors must meet the requirements of industry standards that include air water and structural testing. The design pressure tests were designed to measure wind loads and how resistant windows would be to different types severity of storms.

High speed wind such as wind during a hurricane creates positive and negative pressures and this pressure can tear out windows and doors break glass and force rain into your home. The pressure is caused by wind blowing on and around the subject property. As required by the florida building code every new window installed must meet a minimum design load pressure. It just starts at 2 9 psf for the gateway dp of 15.

National building codes now require testing and certification of windows. What this means is that a lab has carefully tested a window s design pressure by measuring how many pounds of pressure per. Exterior windows and doors shall be designed to resist the design wind loads specified in table r301 2 2 adjusted for height and exposure per table r301 2 3. Design pressure testing measures the performance of fenestration products to withstand positive and negative pressures.

What is design pressure and how does it impact the windows or doors you are considering for your home. Dp stands for design pressure. A dp or design pressure rating is a numerical value given to a building component that represents its ability to withstand a given amount of wind load.