Johnson-level-tool-mfg RAS-1 Bedienungsanleitung PDF herunterladen (Seite 40)

From this we can get the overhang rafter length, noting

thatweareusing2x6raftersgivingathicknessof1-1/2":

ROOF RUN BETWEEN A & B

– SUPPORT RAFTER RUN

– FRONT OVERHANG THICKNESS

= OVERHANG RAFTER LENGTH

63.37"

– 26.69"

– 1.50"

= 35.18"

or in feet:

= 2' 11 3/16"

Lastly we need to ﬁnd the pitched rafter length, the rafter above

thehorizontaloverhangrafter.Inourexample,thepitchedrafter

lengthwillequalthesupportrafterlength(i.e.,50").

STEP 2. RAFTER LAYOUTS:

The support rafter bottom cut

layout(atpointAonFigure21)willbemadesimilartoa

pitcheddooroverhang.Drapethesquare“T”overthetop(or

outside) edge of the support rafter and hold the square ﬁrmly

against the rafter. Then make a mark, using the angle scale,

nexttotheanglethatisfoundbysubtractingtheroofpitch

angle(theroofinchriseindegrees)fromthesupportrafter

inchriseangle.Inourexample,wehave573/4°(forthe19inch

risesupport)minus333/4°(forthe8inchriseroof)or24°.

From this mark, draw a line to the pivot point and you will then

have the bottom cut layout. The support rafter top cut layout

(atpointDinFigure21)issimilartothebird’smouthlayout.

First measure up the outside of the rafter the rafter length

from the bottom cut and then draw a plumb line using the sup-

port rafter inch rise. Now, instead of measuring down the seat

depth, measure down the overhang rafter width and make a

horizontal line going to the roof edge of the rafter.

The horizontal overhang rafter layout is identical to the layout

foraatroofextension(henceitsname).

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Johnson-level-tool-mfg RAS-1 Bedienungsanleitung Seite 40