Jack Rafters - Calculated Industries Construction Master III User Manual

Hip or Valley, "Jack Rafters"
— Set at 16" on-center
You're again working with a 7-in-12 Pitch and
the Run of the common rafter is 20 feet 5 inches.
You want to calculate the length of your jack
rafters at 16 inches o.c.: First, calculate the
common and hip/valley lengths, then the jacks.
COMMENTS
Clear calculator
Enter Pitch
Enter Run
Find Diagonal
Find Hip/Valley
Recall 16 inch o.c.
Find 1st Jack
Find 2nd Jack
Find 3rd Jack
Etc., Etc.
Repeat, until all jacks are found, or when
calculator displays "0 FT 0 IN."
44 — Construction Master III
Jack
Rafters
Plate
16"
KEYSTROKES
[On/C] [On/C]
7 [Inch] [Pitch]
20 [Feet] 5 [Inch] [Run]
[Diag]
Answer: 23 FT 7-41/64 IN
[Hip/V]
Answer: 31 FT 2-51/64 IN
[Rcl] [Jack]
Answer: 16 IN JK
[Jack]
Answer: 22 FT 1-7/64 IN
[Jack]
Answer: 20 FT 6-19/32 IN
[Jack]
Answer: 19 FT 0-1/16 IN
®