Roof pitch is the steepness of a roof expressed as a ratio of inch(es) rise per horizontal foot (or their metric equivalent), or as the angle in degrees its surface deviates from the horizontal. A flat roof has a pitch of zero in either instance; all other roofs are pitched.
The pitch of a roof is its vertical 'rise' over its horizontal 'run' (i.e. its span), also known as its 'slope'. In the imperial measurement systems, "pitch" is usually expressed with the rise first and run second (in the US, run is held to number 12; e.g., 3:12, 4:12, 5:12). In metric systems either the angle in degrees or rise per unit of run, expressed as a '1 in _' slope (where a '1 in 1' equals 45°) is used. Where convenient, the least common multiple is used (e.g., a '3 in 4' slope, for a '9 in 12' or '1 in 1 1/3').
The pitch of a roof has a number of important implications, including:
* **Drainage:** The steeper the roof, the better it will drain. This is important in areas with heavy rainfall or snowfall.
* **Wind resistance:** The steeper the roof, the more resistant it will be to wind damage. This is important in areas with high winds.
* **Snow load:** The steeper the roof, the less snow it will hold. This is important in areas with heavy snowfall.
* **Appearance:** The pitch of a roof can have a significant impact on the appearance of a home or building.
When choosing a roof pitch, it is important to consider the climate in the area, the style of the home or building, and the budget.
Here are some general guidelines for choosing a roof pitch:
* **Areas with heavy rainfall or snowfall:** Steeper roofs are better for areas with heavy rainfall or snowfall. This is because they will drain better and be less likely to collapse under the weight of snow.
* **Areas with high winds:** Steeper roofs are better for areas with high winds. This is because they are more resistant to wind damage.
* **Homes or buildings with a traditional style:** Steeper roofs are often associated with traditional styles of homes and buildings. If you are trying to achieve a traditional look, a steeper roof may be a good option.
* **Homes or buildings with a modern style:** Flat roofs are often associated with modern styles of homes and buildings. If you are trying to achieve a modern look, a flat roof may be a good option.
* **Budget:** The cost of building a roof increases with the pitch. If you are on a budget, a flatter roof may be a better option.
Ultimately, the best way to choose a roof pitch is to consult with a qualified roofing contractor. They can help you assess your needs and choose the right pitch for your home or building.
