Roof Pitch
Computing Your Roof Angle
Introduction:
As
home
owners and do-it-yourself
handy folks
we often contemplate adding an addition such as a
covered porch or storage shed in the backyard or
even a small garage. One of the daunting question is
what should the roof pitch (slope) be and what is
the angle of the roof rafters. Actually the answer
to these questions is not as difficult as they seem.
First off the language of roof
pitch must be understood if
you are contemplating a DIY project that involves
constructing a roof. Roof pitch is usually
expressed as a ratio of the amount of rise in inches
to the run (length) in inches. For example a 5/12
pitch means that the roof will rise 5 inches for
every 12 inches of run, or a 7/12 pitch will rise 7
inches for every 12 inches of run. After we decide
what pitch we want we must determine the angle to
put the rafter to obtain the desired pitch. This can
be determined by using a carpenters framing square
or consulting the chat below for the most common
roof angle.
Given this information a 14 foot
wide add on roof for a sun porch with a roof pitch
of 7/12 the angle would be cut at 30.5 degrees and
the height of the beginning point of the rafter ( at
the point it attaches to the building) would be 8.17
foot. (14 foot / 12 inches = 14, 14x7=98 inches, 98
inches /12 = 8.17 foot).
|
Roof Pitch and
Roof Angle
|
|
Pitch (rise to run)
|
Degree
|
|
1/12
|
4.5
|
|
2/12
|
9.5
|
|
3/12
|
14
|
|
4/12
|
18.5
|
|
5/12
|
22.5
|
|
6/12
|
26.5
|
|
7/12
|
30.5
|
|
8/12
|
33.75
|
|
9/12
|
37
|
|
10/12
|
40
|
|
11/12
|
42.5
|
|
12/12
|
45
|
|
