To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3.
How to get dimensions for a roof.
We multiply the roof length c which is the sum of building length plus the gable end overhangs of the roof by the roof width of slope a that we just figured out above when we computed the hypotenuse of the roof triangle that s why we needed the roof rise number.
The roof area ra is calculated easily.
If a section is 120 feet 37 m x 100 feet 30 m its total square footage would be 12 000 square feet 1 100 m 2.
Multiply the number of roofing squares for a medium pitch roof by 1 12 to 1 25 or by 1 3 to 1 42 for a high pitch roof to get the square roof area.
Keep in mind that the average size of a roof is 1 700 square feet so your total will likely be 10 higher or lower than this figure.
This reveals that the minimum size for the leader pipe is 5.
Given pitch and a horizontal area measurement multiply the horizontal area by a correction factor corresponding to pitch provided in the table below to determine the actual area of the roof to be used in the roofing material calculator.
Depending whether the roof area is measured horizontally possibly from a drawing or photograph a correction factor is necessary to determine the actual area of the roof.
Just multiply the length and width dimensions.
A square simply refers to a 10 x 10 square of roofing.
This is simply 100 square feet of roof.
Things you will need steel tape measure.
To find the squares divide the overall roof area by 100 and then round up.
Be sure to find the area of any dormers on your roof as well.
The first step in a free roofing estimate is measuring the roof dimensions.