QA

How To Measure Roof Slope

How to Calculate Roof Pitch in Degrees First, you need to measure the run of your roof. Next, you need to figure out the rise. Now, divide the rise by the run. Then, divide 1 by your tangent. Finally, multiply this result by 180/π and you’ve calculated your roof pitch!.

What is a typical roof slope?

The majority of North American residential roofs have historically been constructed with a slope between about 4:12 and 9:12. Roofs at the lower end of the range (about 4:12 to 6:12) are relatively easy to walk and work on. (As always proper safety equipment and precautions must be followed when working on any roof).

How do you find the slope of a roof angle?

If you know the roof’s angle in degrees, you can find the roof pitch by converting the angle in degrees to a slope, then finding the rise by multiplying the slope by 12. First, find the slope by finding the tangent of the degrees, e.g. slope = tan(degrees). Then multiply the slope by 12 to get the rise.

How do I determine the pitch of my roof?

The pitch of your roof is determined by the measurement of the vertical rise by the horizontal run. That is to say, the roof pitch (expressed as a ratio) tells you how many inches the roof rises for every 12 inches of depth. So, let’s say a roof rises 6 inches for every 12 inches in depth towards the peak.

What kind of roof do I need for a 2 12 pitch?

A pitch of 2/12 is the minimum for shingles made of asphalt, so your roof just barely makes the cut-off for one of the most popular roofing material options. Resilient asphalt shingles lie much flatter to the substrate than slate, tile and concrete, which keeps water from being easily blown under them.

What is considered a high pitch roof?

A roof with a high pitch is commonly 6/12 – or 6 inches in height for every 12 inches across. When making roof decisions, many people think these roofs require more materials and cost more money. Thus, they are often tempted to go with a low slope. However, 6/12 and higher rooftops are valuable—and for good reason.

How do you calculate the slope factor of a roof?

The roof slope factor is written as “x/12,” where “x” is the vertical distance you measured from roof to level. For instance, if the measurement was 3, your roof slope factor would be 3/12, and you would have a roof with a low slope.

How do you determine the slope?

Pick two points on the line and determine their coordinates. Determine the difference in y-coordinates of these two points (rise). Determine the difference in x-coordinates for these two points (run). Divide the difference in y-coordinates by the difference in x-coordinates (rise/run or slope).

What is a 12 6 roof pitch?

Roof pitch (or slope) tells you how many inches the roof rises for every 12 inches in depth. An Example of a roof pitch would be a “6/12 pitch” which means that the roof rises 6 ” for every 12″ inward towards the peak (or ridge).

How do you figure roof rafter length?

The length of the rafter is given from the long point of the ridge cut at the top down along the top edge the board to the same plumb cut on the rafter’s notch. The next result is the run. This is the horizontal measurement from the outside of the wall to the inside of the ridge.

How do you calculate rafter length and Birdsmouth?

On the rafter, you want to cut, measure its overall depth, and divide it by 3. Using this figure, measure and mark two points on each side of the vertical line, which indicates where the birdsmouth will be cut.

What is the distance between rafters on a roof?

But they do tend to space rafters in one of several industry-standard increments, typically either 12, 16 or 24 inches apart. These spacing intervals are measured “on center,” meaning that the measurement is taken from the center of one rafter’s horizontal surface to the center of the next rafter.

Is a 7/12 roof pitch walkable?

The roof’s pitch is the angle of the roof, usually presented as the inches of vertical “rise” over 12 inches of horizontal “run.” Generally anything above a 7/12 is considered a non-walkable roof and requires some extra equipment and usually some extra cost to the customer.

Can you shingle A 2 12 pitch roof?

The minimum roof pitch for shingles is a 2:12 pitch. Shingles aren’t meant to hold or have sitting water on them. Because of this, the shingle manufacturer’s installation instructions and building codes state you can’t install asphalt shingles on a roof with a pitch below 2:12.

What is the cheapest roof pitch?

Roofers generally consider a low slope roof to be any roof at 3/12 or less, rising no more than three inches per foot of roof. A medium slope roof would be any roof between 6/12 and 9/12, and a high slope roof is any roof with a slope of 10/12 or greater.

Can I use shingles on a low pitch roof?

Most shingles may be applied on roof slopes of 2:12 to 4:12 (a “low slope” roof), providing that the shingles are adequately sealed against wind lift, and special procedures are followed. In many building codes, allowances are made to permit applications of asphalt shingles to low sloped roofs.