18 12 Roof Pitch Factor

You need to first figure out the dimensions of the roof by multiplying.

18 12 roof pitch factor. On blue prints architects engineers usually display the pitch of a roof in the format shown on the image where number 4 represents a rise and number 12 represents a length. The pitch is defined as the slope of the roof and is commonly represented as the ratio of the rise over the run in the form x 12. The roof pitch is a measure of roof steepness. Roof pitch 6 12 roof length including overhangs 40 gable wall length including overhangs 24 enter 6 into the calculator slope factor 1 1180 multiply the roof length by the gable wall length 40 24 960 multiply this.

In our example the roof pitch was calculated as 9 12 which has a factor of 1 25 in the table. As aforementioned there is no standard pitch of a roof. From the roof pitch factor table note down the roof pitch conversion factor corresponding to the roof pitch calculated. The roof pitch factor is also used to calculate the length of common rafters.

Roof is 8 12 pitch and measures at 1900 square feet 1900 x 1 2 2280 2280 1900 380 feet added for pitch if the home measures 20 x 40 and has a 7 12 roof. You write the pitch assuming a run of 12 inches thus the ratio would describe how much a roof rises for each foot of the run. A roof pitch of 4 in 12 4 12 has a rise of 4 and a run of 12. Roof pitch and corresponding angles.

Roof pitch factor valley hip factor 1 12 4 76 1 0035 1 4167 2 12 9 46 1 0138 1 4240 3 12 14 04 1 0308 1 4362 4 12 18 43 1 0541 1 4530 5 12 22 62. The rise is the height of the roof at its highest point and the run is the horizontal span of the roof measured from the roof ridge to the side of the building. This means if a roof rises 4 in the length of 12 your roof pitch would be 4 12 or 18 43 degrees. But the most commonly used pitches range between 4 12 and 9 12.

18 12 1 80 20 12 1 94 22 12 2 09 24 12 2 24 example calculations. To find the total length of a common rafter consider the run to be the horizontal distance covered by the whole rafter from the end of the rafter tail the part of the rafter which extends past the outside of the wall to the near side of the ridge board. For example if you measure 4 inches the pitch of your roof is 4 12.