Roofs with slope of 7 degrees or less.

Figure 4.1.7.6.-C (NBC2020)

v1.0.1

#### Factors

User input values:

q: 1kPa

Importance Factor, ULS: I

C

q: 1kPa

Importance Factor, ULS: I

_{w}= 1.0C

_{e}= (h/10)^{0.2}(but not less than 0.9) = 0.9#### External Wind Pressure

Zone | C_{p}C_{g} | p_{e} (kPa) |
---|---|---|

c- | -5.4 | -4.86 |

r- | -1.8 | -1.62 |

s- | -2.5 | -2.25 |

oc- | -5.4 | -4.86 |

os- | -3.2 | -2.88 |

or- | -3.2 | -2.88 |

c+ | 0.5 | 0.45 |

r+ | 0.5 | 0.45 |

s+ | 0.5 | 0.45 |

#### Internal Wind Pressure

C

_{gi}= 2C

_{pi}= -0.45 to 0.3p_{i} = I_{w}*q*C_{e}*C_{t}*C_{gi}*C_{pi}

p_{i} = -0.81kPa to 0.54kPa

#### Combined Wind Pressure

Zone | C_{pi}=-0.45 p (kPa) | C_{pi}=0.3 p (kPa) |
---|---|---|

c- | -5.4 | -4.05 |

c+ | -0.09 | 1.26 |

r- | -2.16 | -0.81 |

r+ | -0.09 | 1.26 |

s- | -2.16 | -1.44 |

s+ | -0.09 | 1.26 |

oc- | -5.4 | -4.05 |

os- | -3.42 | -2.07 |

or- | -3.42 | -2.07 |

#### End Zone Width

The end-zone width is the lesser of:• 10% of the least horizontal dimension = 0.1m

• 40% of the height of the building (H) = 0.4m

but not less than:

• 4% of the least horizontal dimension = 0.04m

• 1m

**z = 1m**