The roof pitch calculator calculates slope, pitch, angle and rafter lengths, based on input of rise M and run R. Use the diagrams on this page as a reference when inputting rise and run, and while interpreting the calculated results. To determine the finished height of the ridge beamadd the Rise M and the Y height. To determine the Y height, measure from the bird's mouth up the calculated slope X in 12 to the top of the rafter.
This is very useful information for many purposes, especially for roof framing - the slope, sometimes called pitchis calibrated on speed squares. This is useful because sometime you may need to cut a bevel with your circular saw that is not calibrated using roof pitch style - this setting on circular saws is calibrated in degrees.
Rafter Length - The rafter length results, from this calculator, represents the length of line L on the diagram s. Note that this is not the actual length of the rafter. It is the length of this portion of the rafter. If you plan to have overhang, etc. Pitch - Is the incline of the roof represented as the ratio of rise to the span twice the run. If you are calculating rafter length from the center of the ridge beam as shown belowyou will need to subtract half of the thickness of the ridge beam from the top end of the rafter.
Not so. Many factors determine which roofing materials you can use, and one make-or-break factor is the slope of the roof, known as roof pitch. For example, you may think you want classic composite shingles on your roof, but if the pitch is below a certain ratio, you may be forced to install a different type of roofing—perhaps rolled roofing or standing seam-metal roofing.
Pitch is the term used to describe the angle, slope, or slant of your roof. Roof pitch designations are comprised of two numbers indicating a ratio.
Or, the colon can replace the slash, as in or Either way, the notation designates a ratio between two measurements of the roof—a numerator and denominator. The pitch of a roof is nothing more than a ratio that indicates how much rise there is in the roof over a unit horizontal distance.
The flat roofing materials most appropriate to these shallow-sloped roofs include:. Clay or cement tiles can be used on a wide range of roof pitches. For pitches of 2. A great many residential roofs fall into this category. The roofing materials most often used for these pitches include asphalt composite shingles: Traditional 3-tab shingles made with asphalt composite are the most popular type of shingle and are the most flexible in terms of adapting to many roof pitches.
Think of them as taking the middle road in terms of roof pitch—not too flat, not too steep. Wood and slate shingles are used in many of the same types of roofs as asphalt composite shingles, but may not be appropriate for roofs near the lower end, since they are more susceptible to leaking. Wood and slate shingles do not lock together as tightly as other types of shingles.
Most roof materials have a recommended pitch range for which they are most appropriate. The rules can occasionally be broken, but generally, you should not exceed the low range of the recommendation. Numerator: The numerator, or first number, refers to the vertical height measurement of the roof.
Denominator: The denominator, or second number, denotes the horizontal length measurement of the roof. To make things a bit easier, for roofing purposes the denominator is always The denominator remains Two examples at each end of the spectrum:. Visually, this roof appears flat. High-pitched: Roofs on Victorian-era houses were often sharply angled with a steep pitch.
Think of a classic Addams Family haunted house with its soaring peaks and you have a picture of a high-pitched roof. Built-up roofing: Sometimes called tar-and-gravel, or BUR, the modern form of this kind of roof consists of alternating layers of bitumen and reinforcing fabrics.
Rubber membrane: EPDM short for ethylene propylene diene monomer is a true rubber that can be applied to a roof with glue or mechanical anchors.
Standing seam metal: These roofs are made from panels of aluminum or steel joined together in raised seams. They can be used on roofs with pitches as low as. They are also used on much steeper roofs. Built-Up BUR :.
Read More.The roof pitch calculator is a convenient online tool you can use to quickly assess the pitch of your roof to determine the length of rafters you need. After finding out your roof pitch angles, you can use the calculator to perform the calculations for you instead of doing them manually.
This roof pitch calculator or roof slope calculator is a simple, easy to understand tool to use when you need to perform construction work in your home. To use this, you must take the required measurements so you can input them in the required fields. Here are the steps to follow for the roof angle calculator:.
Convert Roof Pitch To Degrees
Roof pitch refers to the slope which the rafter creates. You can assess this in two ways, either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof. Often, you express roof pitch as the ratio between the rise and the run in the form of x You can also calculate roof pitch even without using a roof slope calculator. Use the following formula which also describes a right triangle. Here are the equations you may use to solve for the length of the slope and the rafter:.
Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. As aforementioned, there is no standard pitch of a roof.
How Roof Pitch Affects Your Choice of Roofing Materials
You need to consider the slope requirements of each panel to determine this minimum slope. The profile is the shape taken by the sheets when you bend them to form panels. Express the slope of a metal roof by a ratio which indicates the pitch of the roof. This notes the rise of the roof for every foot of the horizontal run.
In other words, you divide the vertical rise by the horizontal run. Loading Calculator…. Table of Contents.For many people, working out the roof pitch angles can be a bit of a nightmare, especially if you are going to do it yourself and try to manage it all on your own.
Naturally, this does not go down particularly well without the right tools, knowledge and assistance. To avoid this problem from occurring, you should always look for a roof pitch calculator to help you take things a step further. If you are trying hard to work out how to figure roof pitch measurements, the calculator takes away all of those problems for you more or less instantly.
If you are trying to learn how to measure roof pitch calculations accurately, you should really consider the importance of using a calculator.
If you want to learn how to calculate roof measurements, you need to start here. Measurements that you can get from using a calculator will be far more in line with what is expected in the industry, and also will ensure that you can get industry standards correct, as well as making sure that your chosen roof pitch will be safe and secure to use. Calculators will give you the right verdict back so that, whatever you decide, you are left with a roof pitch that you feel happy with.
Various roof pitches need to be edited, used and changed with a calculator to make sure that they are a logistical fit. It always makes sense to the standard roof pitch angle spot on as the benefits of doing so are quite obvious; with the help of these roof pitch degree calculator programs you can make sure that your home is nice and balanced.
If you want to know how to find the pitch of a roof, then, start with a calculator! Even if you want to use a flat roof pitch calculator system, you will be able to find one. This will allow your project to carry the depth and detail in the roof that you wanted, as well as make sure that it will maintain a sturdy and effective nature throughout.
Enter parameters Find pitch from:.
Roof Pitch Calculator
Calculate Result:.What are the factors that influence a shed roof pitch? When you look at pictures of sheds you see that there are a whole array of different shed roof slopes. Is shed roof slope just a matter of personal choice?
Below we go into the historic and practical factors that can influence your choice of shed roof slope. It isn't all science and it isn't all just judgement. Like many things in life a balance has to be struck to get just the right solution for your particular situation. In areas with high rain and snow fall roof pitches traditionally tended to be relatively steep to encourage water and snow to drain and slide off. Whereas in dry areas roofs could be flatter. The occasional rainfall would not have a real chance to soak in and find the weak spots.
With the advent of modern roofing materials such as epdm the importance of roof slope is less. As a roof can be made waterproof even at very shallow, or nominally flat roof pitches. However pitched roofs are still used as roof trusses are a very economic way of spanning between side walls. Steeper roof pitches are better at shedding rain and snow and are used more frequently in wetter colder areas 2. Pitched roofs are attractive and also can be used for additional space for a shed loft Having a steeper pitched roof allows for more space in a shed loft.
This image shows a relatively shallow roof pitch of 15 degrees. The loft space would be much larger with a roof pitch of 45 degrees. Pitched roofs can also be used to incorporate roof lights angled in a specific direction or dormer windows Artists commonly use North facing roof lights to allow cool light into their studios.
Dormer windows such as the traditional gabled dormer or the more modern transom dormer allow in light, add interest to a roof line and can also give some additional space in a shed loft. This image shows a transom dormer. The shed roof pitch has two slopes and the window above eaves level allows additional light into the shed. An important factor to throw into a discussion about roof pitches is local planning rules and regulations Here in the UK there is a limitation on the height of shed roofs when they are close to boundaries, which many sheds are.
Therefore it is very common to see larger sheds that have a very low pitch or flat roof. There are many designs that accommodate this restriction without unduly affecting the appearance of the building.
Find out about planning rules for UK sheds and outbuildings. More modern tiling and felt shingle systems can achieve lower slopes down to about 20 degrees. For slopes below 20 degrees systems such as epdm, fibreglass, metal roofing can be used. For lots more information on which roof finish to use for which slope and indicative costs.
Visit the shed roofing page. This image shows a shed with a roof pitch of 30 degrees with a covering of cedar shingles.A roof protects a house and porch from snow and rain, as well as the heat of the sun.
Adding a covered porch adds exterior space to a house, and providing a roof for the porch moderates the temperature and conditions on the porch. Adding a roof can create drainage problems if the roof pitch is too shallow. However, you can only use this pitch with built-up roofing or specialized synthetic roofing. Covered porches that are near trees or in areas with heavy rains should not use a low-slope roof to avoid trapping debris and water on the roof surface. The covered porch roof pitch should match the existing house.
Buildings with multiple roof pitches do not appear cohesive. The porch should appear to be part of the structure, not an addition pasted on. If it is not possible to match the pitch of the existing roof, use a pitch that is shallower than the roof; do not use a steeper pitch, because the form of the covered porch will overpower or contrast with the main roof. Match the roofing on the covered porch with the main roof. Determine the minimum slope of the roof based on the roofing material.
The minimum pitch for shingles iswhich is equivalent to 4 inches rise to 24 inches run. The minimum pitch for a standing seam metal roof isor 3 inches rise to 12 inches run. The minimum pitch for roll roofing isor 2 inches rise to 12 inches run. The function of the roof in weather and the environment determines the minimum pitch for a roof.
For example, a shingle roof in a snowy region could bebut it is better to have a steeper pitch, such as or even steeper, to shed the snow. Furthermore, a roof in a forest should have a slope of at least to shed the fallen leaves and debris of the forest. Ryan Crooks is a licensed architect with 15 years experience in residential, institutional, healthcare and commercial design.
Crooks is also an instructor, teaching architecture to high school and college students. He has written hundreds of articles for various websites.
Skip to main content. About the Author Ryan Crooks is a licensed architect with 15 years experience in residential, institutional, healthcare and commercial design. Customer Service Newsroom Contacts.The industrial age brought about economical building methods and the prevalence of flat roof construction.
It is a simple and cost-effective method to use for certain commercial construction buildings like warehouses.
Although a flat roof appears to be level, getting water off a flat roof requires a minimum slope, and installing the proper flat roof angle is essential for avoiding water problems in the future. The slope of a roof, or "pitch," is determined by how many inches the roof rises over 1 foot or 12 inches. An example for a steep sloped roof is This means that the rise of the slope goes up or down 8 inches for every 12 inches. To put it in perspective, the angle of this slope would be around 30 degrees.
This is the basis for calculating the angle, which is approximately a 1. This angle may need to change if you choose an alternative building material for the membrane of the roof. A common slope used that covers most materials iswhich means that for every foot, the roof steps up or down 2 inches. How water runs off a roof depends on the amount of rainfall and how quickly it needs to drain. The drainage system of any roof can be located at the edge or in the middle of the roof.
For a large roof, it is recommended to have drains placed at multiple locations within the area of the roof. Increasing the angle of a flat roof will always increase the speed of water movement across the surface. For flat roof drainage, where you place your drains, scuppers and the final material of the roofing is more important. The angle is not significant enough to prevent water from pooling on the surface.
To keep damage like leaks from occurring, water should not stand on a flat roof for more than 48 hours. For areas that have heavy snow or frequent torrential downpours, a flat roof can be problematic. Consider the location of the drains, additional drainage measures and the slope leading to these locations. The structure below must also be able to carry the increased loads when there is standing water or snow. Elizabeth Abbey is a freelance writer from Portland, OR.
She has been writing since focusing on architecture, design and culture. Hunker may earn compensation through affiliate links in this story. Share this article. Elizabeth Abbey. Show Comments.