
39
Thepitchedraftertopcutlayout(atpointCinFigure21)is
thesameasthesupportrafterbottomcutlayout(atpoint
A).Forthepitchedrafterbottomcutlayout(atpointD)
the following equation is used:
BOTTOM ANGLE =
SUPPORT ANGLE + ( 2 x ROOF ANGLE ) – 90°
In our example:
= 57 3/4° + (2 x 33 3/4°) – 90°
= 35 1/4°
Use this equation when the pitched rafter length equals the
support rafter length. We then hold the square tight against
the top edge of the rafter as we did for the top cut and make
amarkatthebottomcutangle(e.g.,at351/4°).Alinefrom
this mark to the pivot point gives us the necessary bottom
cut pattern.
STEP 3. RAFTER PATTERN CUTS:IfFigures20and21are
carefully studied, the rafter pattern cuts can be easily made
followingthepatternsthatwerelaidout.Setyoursawat90°
for all the cuts.
TABLE C
Latitudes for Selected Cities
City, State Latitude N°
Atlanta,GA 34
Bismarck,ND 47
Boston,MA 42
Brownsville,TX 26
Caribou,ME 47
Columbus,OH 40
Fresno, CA 37
Indianapolis,IN 40
Las Vegas, NV 36
City, State Latitude N°
Lincoln,NE 41
Medford, OR 42
Milwaukee, WI 43
Nashville, TN 36
OklahomaCity,OK 35
Raleigh, NC 36
Salt Lake City, UT 41
Tallahassee,FL 30
Toronto, Canada 44
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