QUESTION: Why do certain door products rate a certain p.s.f like -60/+60 then lower ratings are shown throughout the product approval?
Usually, the higher door pressure performance are not taking the water testing & infiltration conditions into consideration. A deeper search into the evaluation will likely reveal limitations of performance if water infiltration is required.
So What Is Water Infiltration?
Also valid for IBC 2018 1709.5 with modifications (click here to see)
- Door assemblies installed where the overhang (OH) ratio is equal to or more than 1 need not be tested for water infiltration. The overhang ratio shall be calculated by the following equation:
OH ratio = OH length/OH height
OH length = The horizontal measure of how far an overhang over a door projects out from the door’s surface.
OH height = The vertical measure of the distance from the door’s sill to the bottom of the overhang over a door.
NOTE: Pass-through windows for serving from a single-family kitchen, where protected by a roof overhang of 5 feet (1.5 m) or more shall be exempted from the requirements of the water infiltration test.
…at which time the door will have to be underneath an overhang per section 1709.5.1 of the 7th Edition (2020) Florida building code. Once water resistance is required, the structural positive pressure may be lower. This is where you are likely to see +40/-60 so of these, (60/60 and 40/60) the lowest will govern. On doors there is usually a variation of thresholds with different ratings.
Excerpt from 1709.5.1 Exterior windows and doors.
Exterior windows and sliding doors shall be tested and labeled as conforming to AAMA/WDMA/CSA101/I.S.2/A440 or TAS 202 (HVHZ shall comply with TAS 202 and ASTM E1300 or Section 2404). Exterior side-hinged doors shall be tested and labeled as conforming to AAMA/WDMA/CSA101/ I.S.2/A440 or comply with Section 1709.5.2.
Products tested and labeled as conforming to AAMA/WDMA/CSA 101/I.S.2/A440 shall not be subject to the requirements of Sections 2403.2 and 2403.3. Exterior windows and doors shall be labeled with a permanent label, marking, or etching providing traceability to the manufacturer and product.
Last Update: April 7, 2021