4/12 Pitch Angle
4/12 Pitch Angle: So, the 4/12 roof pitch angle is about 18.4°.
What Is the Slope of a 4 12 Roof Pitch?
A 4/12 is a roof slope that rises by 4 inches for every 12 inches across. This forms an angle of 18.5° between the horizontal section and the roof and creates a gentle incline that is seen as a midpoint between a low-pitch and medium-pitch roof.
A 4/12 roof pitch can also be expressed as 4 over 12 and when you're talking to a roofer, this is the most common way you'll hear it explained because it's easy to say in conversation.
Another way to express a 4/12 pitch is "4 and 12."
In this pitch, the four is your roof's rise and the twelve is the roof's run.
The roof's incline increases by four feet for every 12 feet of horizontal measurement.
Also Read: How to Fix Squeaky Stairs
Roof Pitch is a term describing how steep or flat your roof slope is. The combination of two numbers is used to display or show the roof pitch. The two most common methods (4/12 or 4:12) are used for marking the pitch of a roof.
On blueprints, architects & engineers usually display the pitch of a roof in the format shown on the image where the number (4) represents a rise and the number (12) represents a length. This means if a roof rises 4' in the length of 12', your Roof Pitch would be 4/12 or 18.43 degrees.
The pitch of the roof is the measurement of the roof’s slope expressed in a ratio, fraction, percentage, and in degrees, there is no single standard for the pitch of the roof used on all sloped roofs, determining factors such as roofing material and local climate condition help to determining the appropriate range of the pitch for a given building or structure. But the 4/12 roof pitch is the most common lowest slope for standards shingle installation for residential roof pitch in which the roof rafter rises 4 inches for every 12 inches or 1-foot horizontal distance or run.
The 4/12 roof pitch step is enough to shed water quickly and also be comfortable for walkable. It is most commonly considered the lowest slope for standard shingle installation. 4/12 roof pitch express in fractions, percentages, ratios, or an angle.
In the earlier time from the beginning of civilization, people are always looking for houses built of timber covered with roofs to prevent heavy rainfall and snowfall conditions. The design and construction of roofs are depending on many factors but one of the most common important factors is the climatic and weather condition of your surrounding areas, in your cities and countries.
The area which has heavy rainfall and snowfall requires good drainage for the roof, roof drainage depends on the slope of the roof provided, based on the slope of the roof it is categorized into two types flat roof and pitched roof or sloping roof. These are two types of roof structures based on slop.
The flat roof is a type of roof in which the slope is generally less than 10°, which only enables to ensure adequate drainage of rainwater in low to moderate rainfall regions. A pitched roof is a type of roof comprising a sloping surface or surface with an angle of usually over 20°, generally, it slopes downward in one two, or more parts depending on design and construction.
The pitch of a roof lower than 4/12 has a slight angle called a low slope roof, pitches of less than 2/12 are considered flat roofs, pitches higher than 9/12 are called steep slope roofs, and pitches ranging between 4/12 to 9/12 are considered conventional roofs pitch suitable for most of the residential house. In this article, we only explain about 4/12 (4 on 12, 4 over 12, or 4 in 12) roof pitch angle and their height.
Also Read: How Much Does It Cost to Level a House
Pitch Fraction
Historically the word "pitch" meant a ratio between the ridge height to the entire span/width of the building or a ratio between the rafter length to the building width. And back then, the ridge was typically in the middle of the span. This is no longer the case in modern building practices. The ridge can be placed anywhere in the span, from the direct middle to either span endpoint.
A roof that rises 8 feet over a 24-foot span was said to have a “1 to 3” pitch. If the rise is 4 feet over a 24-foot span, then the roof pitch was said to be “1 to 6.”
The pitch can be expressed numerically as a fraction. The pitch fraction represents a certain amount of vertical rise over the entire span.
For example, given a roof with a rise of 4 feet and a span of 24 feet, the pitch is “1 to 6” pitch, which can be expressed as a fraction of 1/6. A “12 to 24” pitch is expressed as 1/2.
The term “pitch” and “slope” are often used interchangeably, which is incorrect. They do not mean the same thing. And slope provides more valuable information than pitch, as defined in this article.
Also Read: Types of Arch Windows
Why It’s Important
The roof pitch is necessary for two things – one, estimating the amount of material to be ordered for the job, and two, knowing what materials are suited for the roof. But, again we are jumping ahead of ourselves. Before we get started with all that we need to find out the pitch of a roof.
