# What Is Considered A Steep Roof Pitch?

by Heather Robbins
Understanding roof pitch is vital, especially when having any work done to your home. But, what exactly constitutes a steep roof pitch versus a low pitch? According to OSHA, a

Understanding roof pitch is vital, especially when having any work done to your home. But, what exactly constitutes a steep roof pitch versus a low pitch?

According to OSHA, a steep roof has an angle of at least 18.43° and a rise-to-run ratio of 4:12 or higher. However, some architectural styles necessitate a steeply pitched roof. The roof slope is harsher than usual in these situations. And any with a rise-to-run ratio of 12:12 and an angle of 45° or higher falls under it.

Understanding how roof pitches are calculated, what to think about when selecting steep roofs, their benefits, and drawbacks, and what different rise-to-run ratios signify are all helpful. To assist you in deciding how steep your roof should be, this article goes into great detail on these topics.

## How Do You Measure Roof Pitch?

A steep roof is one that has a rise-to-run ratio of at least 4:12 and an angle of 18.43°. But what exactly does this mean?

A roof’s pitch typically refers to how steep it is. Additionally, the slope is calculated as the rise in inches per horizontal foot (or the metric equivalent). The vertical rise over the run or span of a roof is another way to describe the pitch of a roof.

Roofs also form an inclination of deviation out from the horizontal plane as long as they are not flat. In other words, if the ratio is 4:12, which is where steep roofs start, then the roof rises 4 inches for every 12 inches of span. The 18.43° threshold results from that.

The run, which is always 12″, is the customary unit of measurement for roof pitches (12 inches). Because one foot is made up of 12 inches, the number 12 is significant.

A steep roof (26.57 °) is one that has a slope of 6/12. A pitch of 8/12 (33.69 °) is more vertical, though. The sharpest of the three roofs has a slope of 10/12 (39.81 °). Furthermore, any roof that has a 12:12 (45 °) pitch has reached the dramatic pitched-roof zone.

It’s important to keep in mind that although flat roofs appear to be entirely horizontal, they might not necessarily be. For drainage purposes, sure, flat roofs have a baseline pitch of 0.25:12. Others, however, have a slope of 0/12, which equals 0° or 180°.

## What Factors Determine How Steep a Roof Pitch Is?

Wanting a steep roof is perfectly acceptable. The ideal slope of your roof depends on several things. The critical factors to take into account while selecting a roof slope are listed below.

### The Manufacturer’s Warranty

Roofing warranties typically last for around two decades, during which contractors will fix any issues for nothing or at a significant discount. However, whether you strictly adhere to the installation instructions will determine whether you may take advantage of the guarantee.

The manufacturer specifies the minimum roof pitch for many goods. Keep in mind that the threshold they established can be higher than the minimum roofing slope specifications given in your local building codes.

Let’s say you disregard the steepness recommendations. If so, you could nullify your roofing warranty, making you responsible for any roofing failure and any necessary reconditioning even before the warranty period has ended.

### Local Building Codes

The steepness of the roof pitch for high-sloped roofs will depend on your local building codes. And while determining how you should build, these rules probably take into account your environment, the architectural style, and the roofing materials.

For instance, don’t be shocked that experts would advise steeper roofs to boost performance in regions like New York or Chicago, which are renowned for their amount of snow.

However, since there isn’t much precipitation to worry about in arid regions like the Arizona desert, flat or low-sloped rooftops would be preferable.

### The Roof’s Functionality

It would be preferable to take your roof’s usefulness into account before deciding on its steepness. It is simpler to install anything that will remain on the surface for an extended amount of time the lower the roof slope.

For instance, a flat or low-sloped roof is more suited for installing solar panels. Such panels are simple to install and maintain. Additionally, you can tilt the panels to take advantage of sunshine from a specific direction.

However, solar panels work best when angled at 30° or slightly higher degrees. Additionally, solar panels are not the best choice for steeper roofs with pitches higher than 40°.

As a result, while you might get some sunlight from one way, as the day wears on, sunlight from the other direction may be blocked by the steeper roof parts. Your solar panels will then operate horribly because they won’t be able to store as much energy as they should.

Additionally, installing and maintaining solar panels on a steeper roof is significantly more difficult because it must overcome gravity. Additionally, your panels could not receive enough sunlight.

Solar panels would not work well for dramatic pitched roofs, but they could be ideal for water collection. In contrast, flatter roofs have a tendency to dissipate water fast and lessen the chance that it may be contaminated. Therefore, even with little rainfall, you will get cleaner water much sooner.

### Architectural Property Design

Your preferred architectural property design will have a big impact on the roof pitch. This is true because roof shapes and slope designs partially define certain architectural styles.

In general, Gothic and Elizabethan home designs offer drama. As it is usual for Elizabethan residences to have longer rafters than spans, these houses fall under the category of dramatic pitched roofs because their angles exceed 45 degrees (e.g., 16:12).

Very steep gable roofs are another characteristic of Tudor dwellings. On such sites, it is typical to see rooftops with pitches ranging from 10:12 to 14:12.

In contrast, Gothic architectural designs typically have a rise equal to the run (for example, 12:12), which results in roof pitches of 45°.

Roman residences can be quite steep. As a general guideline, rafter lengths should be one-third of the span. The 4:12 steep roof pitch threshold can therefore be met. Some, though, are lower than that.

### Your Building and Renovation Budget

You should be prepared to spend more money on building and renovating your roof the steeper you want it to be.

More safety precautions must be taken to protect anyone installing or replacing a steeper roof. These consist of safety net systems, personal fall arrest, and railing systems with toe boards.

Workers need to take these precautions on highly steep rooftops since the steeper pitch makes it more challenging to work on. Additionally, they have a higher chance of falling and getting hurt. Further, their equipment and debris can fall from the roof and hurt those below.

However, implementing those safety measures frequently has a cost. Whether you were repairing and replacing some of its parts while renovating the roof or installing the roof for the first time, you would have to spend extra on them.

And that isn’t the only difficulty. The majority of the time, the roofing components must be assembled on the ground by the construction professionals.

As there is no room to temporarily keep them on the roof surface while workers install them, handling something straightforward like a bundle of shingles becomes challenging. Additionally, the steep incline makes it more difficult to carry multiple items at once because it calls for more endurance.

Because of the logistical difficulties, you could have to pay more on equipment to transport roofing materials and personnel because contractors would need more time to complete their work. Once more, you will be responsible for covering all costs.

Due to these factors, steep roofs typically cost more than flat or low-sloped roofs. Therefore, it would be beneficial if you had enough money set aside in your budget to cover any problems that might arise during installation or maintenance.

Due to the climate in the area, wherever you live will primarily influence exactly steep your rooftop will be.

Steeper rooftops guarantee that precipitation drains swiftly, protecting their integrity in places with heavy snowfall, strong winds, and significant rainfall.

For instance, you will see many steep gabled roofs in the cold and temperate regions of Northern Europe and America. In order to better absorb the snow or rain that frequently hits the rooftop, these roofs have high slopes.

In general, you might want to think about a steeper roof pitch than usual if you reside in a location where drainage will be a problem. However, remember that some steep roof types could need extra support against powerful gusts.

On a steep slope, you can utilize a variety of roofing materials. Others, however, are considerably better suited to flat or low-sloped roofs.

Your local building regulations and what they say about the roofing material you wish to install will be your largest challenge. You may end up paying dearly down the road if you don’t follow the rules.

Additionally, if you want to utilize a specific roofing material, you might need to adjust the slope of your roof, add more materials, or choose a less appealing option.

Materials like slate, wood, metal, concrete, asphalt, clay, wood shake, shingle systems, and mineral-surfaced roofing are suitable for a steep roof pitch. They can be installed on roofs with a 4:12 or greater slope.

A double underlayment coating may be necessary to enhance the performance of particular roofs. Additionally, some EPDM and TPO membrane components are not appropriate for installation on roof slopes greater than 12:12. Therefore, they cannot be used on a steep roof.

Heather Robbins

Heather is a passionate writer who loves anything DIY. Growing up, she learned everything from home repairs to design, and wants to share her tips with you. When she's not writing, she's usually hiking or searching for her next DIY project.

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