THOMSON Construction Master Pro - Page 13

Sample
Rafters
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Chapter 6 69
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EXAMPLE 6.7
One section of roof having a 6-in. pitch and a run of 9⬘-6⬙ is to be joined
with another roof section having an 8-in. pitch. Using the 6-in. value as the
regular pitch, find the length, plumb, level, and cheek cut angles for the hip
rafter and all jack rafters. Use a uniform rafter spacing of 16⬙ o.c..
Solution:
KEYSTROKE DISPLAY
First, enter the regular pitch and run, check that the calculator has a stored
rafter spacing of 16⬙ o.c., and then enter the irregular pitch:
6 i p
PTCH 6 INCH
9 f 6 i R RUN 9 FEET 6 INCH
1 6 i ß 5 T OC 16 INCH
8 i Ç H (Ir/Pitch) IPCH 8 INCH
Successively pressing the H key will now display the length of your ir-
regular hip rafter, as well as the values for plumb, level, and both cheek cut
angles:
H
IH/V 12 FEET 9-1/2 INCH
H PLMB 21.80°
Notes
Copyright © 2007 by Calculated Industries, Inc.
and Thomson Delmar Learning
Construction Master® Pro Workbook and Study Guide
Common Rafter–Regular Pitch
Common Rafter–Irregular Pitch
Irregular Jacks
Regular Jacks
16” o.c.
16” o.c.
Irregular
Hip
Figure 6-8