How do I determine the elevation of my roof?

Quote from the video:
Quote from Youtube video: The easiest way to find the pitch of your roof is simple geometry you're finding the rise. Over the run. So how much the roof goes up over one foot. So we measure one foot on our level.

How do you determine the slope and height of a roof?





How to Calculate Roof Pitch in Degrees

  1. First, you need to measure the run of your roof. …
  2. Next, you need to figure out the rise. …
  3. Now, divide the rise by the run. …
  4. Then, divide 1 by your tangent.
  5. Finally, multiply this result by 180/π and you’ve calculated your roof pitch!


How is solar elevation angle calculated?

The following formula for the elevation angle at solar noon can be determined:α=90+φ−δα=90+φ-δwhere: φ is the latitude of the required location (positive for the northern hemisphere and negative for the southern hemisphere).

How do you find the slope of a roof?

Quote from the video:
Quote from Youtube video: Which is the distance from the Attic joist to the ridge. And divided by the run and the run is half of the distance between the front and back of the walls of the house.

How do you calculate a roof?





Multiply your house length by your house width to get the area. (For example, 40 feet x 30 feet = 1,200 square feet.) Next, multiply the area by your roof’s pitch. (1,200 x 1.05 = 1,260 square feet.)

What is the best slope for a roof?

For metal panel roof systems, NRCA recommends slopes of 1/2:12 or more for structural panel systems and 3:12 or more for architectural panel systems. For asphalt shingle, clay and concrete tile, metal shingle, slate and wood shake and shingle roof systems, NRCA recommends slopes of 4:12 or more.

How do you calculate a 2% slope?

To calculate percent slope, divide the difference between the elevations of two points by the distance between them, then multiply the quotient by 100. The difference in elevation between points is called the rise. The distance between the points is called the run. Thus, percent slope equals (rise / run) x 100.

How do you calculate roof pitch multiplier?

Once you know your roof slope expressed as “X-in-12″ (rise-in-run), the roof pitch multiplier is determined by finding the square root of ((rise/run)² + 1).

How do you calculate ridge height?



Quote from the video:
Quote from Youtube video: For the thickness of the ridge. So for this time around we need to calculate. The total run minus half the thickness of the ridge in order to get our total Ridge height.

How do I calculate a rise?

Subtract the difference in elevation between two points on a hill to calculate the rise. The elevation could be determined by an altimeter or you could use a topographic map. As an example, you might read 900 feet at the top of a hill and 500 feet at the bottom, so subtract 500 from 900 to get a rise of 400 feet.

What roof pitch is 30 degrees?

7/12 roof



A 30° roof pitch is roughly the same as a 7/12 roof pitch. To convert from degrees to the American ratio: Find the tangent of the angle, tan(angle). This gives you the pitch of the roof.

How do you figure roof pitch and rafter length?

the rafter member will be longer. Pitch – Is the incline of the roof represented as the ratio of rise to the span (twice the run). For example, if the roof rises 4 feet and the span is 16 feet (twice the run), then the pitch is 4/16, or 1/4.

How do you calculate rafter angles?

Quote from the video:
Quote from Youtube video: Doing any math. Number two is how wide your wall plate is that the bottom of the rafters gonna sit on in most cases it would be a 2×4 or 2×6. And the third thing you'll need to know is a measurement.

What size rafters do I need for a 20 foot span?

As per general rules and guideline, for 10 -12 foot span, generally you need 2″×6″ size of rafter, for 15 -16 foot span, you need 2″×8″ rafter, for 18 – 20 foot span, you need 2″×10″ rafter & for 24 foot span, you need 2″×6″ size of rafter placed at 16″ apart from centre.

How much pitch do I need for a lean to roof?



To guarantee water drainage, a roof should have a slope of at least 1/8 inch per foot of horizontal run, but that’s a bare minimum. A slope of 1/4 inch per foot is better and specified by some building codes.

What is the minimum pitch angle for a pitched roof?

2:12 pitch

The minimum roof pitch for shingles is a 2:12 pitch.



If your roof is less than 2 vertical units (inches or feet) up for every 12 horizontal units out, it’s considered low slope.

How much slope should a patio roof have?

Slope is a ratio of inches per foot, the minimum slope is 1/4″ per foot and the maximum slope is 1″ per foot, the maximum slope is the most the cover can be pitched and the roof panels maintain a proper contact with the hanger and beam.