Slope of roof will vary depending on the climate in which a building is built. Some houses in New England, Norway, and other places with harsh winters have vertical pitches. Some walls are even covered with roofing shingles to keep out the elements. Conversely, in deserts, roof angle tends to be flatter, as there is little precipitation to be kept off the structure. Slope of roof increases on either side of the tropics, with roof angle increasing as the climate gets ever more humid.

You can use a simple equation, called a roof slope calculator or roof calculator, to determine a roof pitch or slope of roof. Essentially, it is a fraction that helps determine how many units up and across a roof is. For example, a three-twelfth pitch would have a very low slope, while a nine-twelfth pitch would have a very high slope.

Climate Considerations in Roof Pitch

Climate is the key consideration in roof pitch. The best roof design for any structure depends on the weather it will have to withstand.

A steep roof angle offers advantages in wetter climates, where a higher roof pitch allows the roof to easily shed snow, ice and rain. Pitched roofs can even offer more storage or living space in attics. Though more costly, a pitched roof will last much longer.

A home with a low slope of roof is much cheaper to build, and is much more energy efficient. Flat roofs do not last nearly as long, however, and are more prone to leaks.

Best Roofs for Climatic Conditions

The best roof designs and materials depend a lot on their slope and pitch. Here are some climatic aspects of slope of roof and roof pitch:

• Adobe flat roofs are common in the dry climate of the American Southwest.
• Broad hipped roofs with high roof pitch work well in coastal, humid climates where there is a lot of rain.
• Flat roofs are not really flat, but have very slight slope of roof to allow for drainage.
• Gabled roofs with high slopes are found in high snowfall areas, to allow snow and rain to easily slide off the roof.
• Hip roofs best withstand hurricanes, as the slopes on all sides help regulate wind damage.
• Reflective roofs help houses in hotter regions stay cooler.

Slope of Roof and Cost Factors

The steeper your roof angle, the higher the cost, as a steeper roof requires more materials to build. A project involving a steeply sloped roof will also be costly to build or repair, as they are more dangerous to work on. A higher roof pitch also means that there is more area to cover, and thus more roofing materials will be needed.

Even with these added cost factors, however, a sloped roof will last far longer than a flat one. A home with a steep roof angle can withstand more rain and snow due to its pitch, allowing for drainage.