U
SER
’
S
G
UIDE
— 87
Common Rafter Length
If a roof has a 7/12 Pitch and a Span of 14 Feet 4 Inches, what is
the Point-to-Point length of the Common rafter (excluding the over-
hang or ridge adjustment)? What are the Plumb and Level cuts?
KEYSTROKE
DISPLAY
1. Find Diagonal or Point-to-Point length of the Common rafter:
o o
0.
7 i p
PTCH 7
INCH
1 4 f 4 i ÷ 2 =
7
FEET
2
INCH
R
X 7
FEET
2
INCH
d
R 8
FEET
3-9/16
INCH
2. Find Plumb and Level cuts:
d
PLMB 30.25644°
d
LEVL 59.74356°
Common Rafter Length —
Pitch Unknown
Find the Common rafter length for a roof with a Rise of 6 Feet 11-1/2
Inches and a Run of 14 Feet 6 Inches. Solve for the Pitch in
Degrees and in Inches.
KEYSTROKE
DISPLAY
Find Diagonal and Pitch:
o o
0.
6 f 1 1 i 1 / 2 r
Y 6
FEET
11-1/2
INCH
1 4 f 6 i R
X 14
FEET
6
INCH
d
R 16
FEET
1
INCH
p
PTCH 5-3/4
INCH
p
/
_Ø 25.63565°
