A Comprehensive Guide to 4 Pitched Roof Design

A pitched roof is a classic design that's been a staple in architecture for centuries. It's characterized by a steeply angled roof that allows snow and water to run off easily.

The four main types of pitched roofs are gable, hip, shed, and flat. Each type has its unique features and advantages.

Gable roofs are the most common type of pitched roof, making up about 70% of all roofs in the US. They're easy to build and maintain, but can be prone to leaks if not properly sealed.

Hip roofs, on the other hand, have slopes on all four sides, making them more resistant to wind and snow. They're a popular choice for homes in areas with harsh weather conditions.

A roof's pitch is a crucial aspect of its design, and it's not just about aesthetics. The pitch refers to the number of inches a roof rises for every 12 inches of depth.

A common way to express pitch is as a ratio, such as 4/12 or 5:12. This ratio represents how much the roof rises in height for every 12 feet in width.

Roofs with a pitch between 4/12 to 6/12 are considered standard and quite common. They're a good balance between water runoff and structural integrity.

The 5:12 roof pitch ratio is a good example of a standard pitch, where the roof rises 5 feet in height for every 12 feet in width. This is a popular choice for many homes.

Anything lower than 4/12 is considered a low-sloped roof, while 2/12 is considered a flat roof that's still angled to assist with water runoff. These types of roofs are less common but still suitable for certain climates and designs.

Higher pitched roofs, like 9/12 pitches, are very highly angled and are designated steep-slope roofs. These are typically made for preventing snow and ice build up in northern climates.

You can calculate roof pitch in several ways, but one common method is to use a level and a tape measure in your attic access. Place a level on the underside of a rafter, making sure it's level, and measure the distance between the rafter and the level in inches at the 12-inch mark.

The result is your pitch, which is simply the number over 12. For example, if you measure 14 inches, your pitch is 14 over 12.

Alternatively, you can use a 4-foot-long board, a bubble level, and a tape measure to determine roof pitch while standing on a roof. This method involves placing the board on the peak of the roof, raising or lowering it until you get a level reading, and then measuring vertically from the end of the board to the roof.

Here are the steps to calculate roof pitch from a ratio:

For example, the roof pitch ratio 5:12 means that for every 12 horizontal feet, the roof changes 5 feet in vertical height.

Roofers typically measure roof pitch in one of two ways: by marking a level at 12″ and measuring the distance from the level to the roof's surface, or by measuring from the underside of a rafter on an overhang at the bottom of the roof.

Calculating roof pitch can be a bit tricky, but don't worry, I'm here to guide you through it. You can calculate roof pitch by positioning a level on the underside of a rafter in your attic and measuring the distance between the rafter and the level in inches. This number over 12 is your pitch.

If your roof has a simple gable, you can calculate the pitch by dividing the slope by two, where the measurement wall to wall is twice the size of the run or the wall to the ridge horizontally. This method is a bit more straightforward than the first one.

Alternatively, you can use a bubble level, a 4-foot-long board, and a tape measure to calculate the roof pitch from the roof itself. Place one end of the board on the peak of the roof, and then raise or lower the board until you get a level reading. Measure vertically from the end of the board to the roof and note the measurements.

If you're dealing with a roof pitch ratio, you can calculate the pitch by dividing the vertical feet by the horizontal feet. For example, a roof pitch ratio of 5:12 means that for every 12 horizontal feet, the roof changes 5 feet in vertical height.

Here's a rough guide to help you understand how different roof pitches affect the roof area:

Keep in mind that most residential roofs are between flat and medium pitches, while industrial buildings often have more extreme angles.

If you're building a modern-style home, you'll often find roof pitches with lower angles, typically ranging from 0.25:12 to 3:12. These are commonly found in urban areas and contemporary-style houses.

Roofs with pitches as low as 1:12 are not uncommon, especially in homes built in the 1960s. These roofs have a barely negligible slope to help drain water and visually appear flat.

For shallow-sloped roofs like these, you'll want to use flat roofing materials. Some popular options include:

Standing Seam Metal is a versatile option that can be used on both shallow-sloped and steeper roofs, making it a great choice for many builders.

Flat roofs aren't completely flat, but rather have a very slight pitch between 1/2:12 and 2:12, which translates to 4.2 percent to 16.7 percent.

Low-pitched roofs have a slightly steeper pitch than flat roofs, but still below 4:12, or 33.3 percent. This can make them harder to maintain, as they tend to collect water and debris.

Conventional roofs are safe to walk on and easy to construct, with a typical pitch ranging from 4:12 to 9:12, or 33.3 to 75 percent.

High-pitched roofs have a pitch that can be as high as 21:12, or 175 percent, and often require additional fasteners for safety and functionality.

Here are the different types of pitched roofs, summarized: