The roof pitch can be described as the rise under vertical consideration of the roof being divided by its horizontal span or run. The run is the length or measure of the roof along a horizontal plane. The word pitch in this term is an old English word used to describe the angle of something from its horizontal axis, and not related to any material such as asphalt or wood shingles. The pitch is usually expressed by the rise followed by the run. The rise is then divided by 12. What this does is give the incline ration for every twelve inches or one foot of a run.
How To Calculate Roof Pitch?
Pitch is of great importance in design and building since it determines the steepness of a roof and can also be used to estimate the cost of materials and labor during construction. There are different ranges of pitch. They include the following:
- Flat Pitch – ½:12-2:12; Mainly considered as flat although it has a slight slope that enables water to drain freely.
- Conventional slope pitch – 4:12-9:12; A roof whose run is 10 feet and rise has four inches.
- Very sloped roof – 12:12 or greater; Considered a very steep pitched roof that needs special care in construction because it could be dangerous for workers.
How do you convert the roof pitch into degrees?
The most effective way of converting the roof pitch into degrees is to use a converter. The roof pitch used to be mainly determined by the type of material that was used. Nowadays, it is mostly based on aesthetic preference and weather considerations like snow load among others. The slope angle range of roofs runs from 0.75 degrees for flat roofs to about 30 degrees for very steep roofs. You can also convert pitch to degrees by dividing the rise against the run and getting its corresponding measurement. For example, if the pitch of the roof is 7:12 and its rise is 4 inches, then it can be converted to degrees by dividing 4 by 12 which gives you a 30-degree pitch.
If unsure about the roof pitch, you can measure it using an inclinometer or use a method called the shadow-stick method where you place a stick in a straight line with the sun and mark it on the ground. This way you can calculate the roof pitch by measuring how much the shadow has moved from where you placed the stick before noon until just afternoon. You can use an inclinometer or a scale to measure pitch. Another method is using a clinometer which is a straight stick made of metal or wood with a pair of sights, one on the top and one at an angle to measure your roof pitch. These are some ways you can calculate roof pitch in degrees, whether it’s done manually or using a converter.
The pitch roof angle has a significant effect on the replacement cost of the roof. A steep roof will shed water quickly but it’s quite hard to work on. The pitched roof can also affect the interior temperature when it is hot outside. Roofs that have a lower pitch are quite easy to work on and can protect the building from water seepage because of their low angle. The harsh weather conditions prevailing in high altitudes also affect roof pitch and its steepness. High elevation often creates strong winds that may blow off any unsecured item on the roof, so durability is very important in these areas. This is why it is advisable to have an experienced structural engineer design your roof for you.
Factors to consider
A roof may appear flat but it also has a pitch angle. You will find that the pitch is always very small for this type of roof, making it one of the simplest to build. The main use of flat roofs is as garden areas or self-storage spaces among others. For flat roof construction, you can use tar paper due to its weight and weather resistance or other heavy materials. Snow usually accumulates on the flat roofs if not properly cleared. This is so because of their low angle and can cause injury or even death by collapse if not handled carefully. The roof pitch is mostly determined by the style you want to achieve since it varies depending on the country of use, cultural preference, aesthetic considerations among other factors. However, you should consider other factors like moisture, snow load, wind among others to determine the proper pitch.
- For snow loads, your roof should have an angle of 4/12 or greater to ensure that snow does not accumulate on it. Roof angles less than 4/12 often cause collapse due to the weight of the accumulated snow.
- Snow load requirements also vary depending on location. For example, in dry and desert areas like the US southwest, the minimum pitch of a roof is usually 7/12. If you live in high elevations where it is windy, make sure your roof is steep to avoid strong winds from blowing it off completely or into other buildings.
- Avoid using low angles for your roof because this will make it easy for leaks to form as well as attract more dirt and moisture. In addition, you will find that it takes a longer time to heat or cool the interior of your building.
- In areas where there is heavy rainfall, use a steep pitch because this will help water drain from your roof quickly and prevent damage to your structure.
- You should also consider high seismic activity in your area when designing your roof pitch. High angles fireproof structures are better against earthquakes and will prevent their collapse completely when exposed to severe shaking by an earthquake.
- For aesthetic considerations, use a low pitch if you want the building to appear sleek or even have a stylish appearance. Low-pitched roofs give a unique look to any building and can improve its aesthetics.
- Building construction material is also another factor that affects the pitch of your roof. If you use wood, brick, or concrete in your building construction, then you should normally have a steep pitch of 12/12. This will help water drain off quickly when it rains.
- You can also use metal roofs for commercial buildings because they are weather-resistant and easy to install. However, consider the region where you will be putting up your commercial building before doing so because some of these roofs are not ideal for hot regions while others are not recommended in colder areas due to their weight.
As you can see, calculating roof pitch in degrees is quite easy. Just make sure to consider the preferences of your country, climate, and other factors. Pitch angle can help you achieve the look that you want for your building, protect it against weather conditions like snow or rain as well as earthquakes. It also affects the durability and cost of construction materials used in your roof.