Carpentry

I i

iutti)^^ ;

-:

IRA

SAMUEL

GRIFFITH

Chairman

of the

Manual

Arts Department University ofMissouri

THE

MANUAL

ARTS

PRESS

IRA

SAMUEL

GRIFFITH FOURTH EDITION, 1919

ACKNOWLEDGMENTS

To

_my

_father, whose _{patient instruction}

and

forbearing oversight during the _{period of}

car-pentry apprenticeship has

made

possible the practical aspect ofthis _{present volume, grateful}

acknowledgmentis made.

Acknowledgment is also

made

_of assistance derived

_jrom

the various trade _magazines

and

from

the

_few

bookson_carpentry.

Credit is due

Mr.

franklin G. _Elwood, Peoria, for most of the excellent _drawings

which

_accompany

and

_clarify the text.

A

number

_of the _drawings were penciled by Gordon _Kellar, Boston.

The

_photographs are

thework _of

James

F.

_Barham,

_Columbia,Mo-.

PREFACE

IT

is theauthor's

_hope

that the following text

_may

beofservice

to apprentices to the trade, to vocational

and

trade school

students,

and

to

manual

training students.

The

author's experienceas a carpenter leads

him

tofeelthat not afew

journey-man

carpenters

may

find theirhorizon

widened

and

theirusefulness asframersof theunusualroofincreased

_by

_{a study}of

_Chapter

IV

where

an

effort has

been

made

to indicate

how

the _principles

in-volved in _framing the _square

and

_octagonal roof

_may

_be

"gen-eralized" so as to

make

_possible theirapplication to roofs of

any

number

of sides.

_Beyond

_this, the

book

makes

claims to _being

nothing

more

than

an

elementary treatise of the essentials of

carpentry.

No

_apologyisoffered for

_making

useof_{trigonometric solutions} of _{plane right triangles} as a basis for _developing generalized roof framing principles in ChapterIV.

There

is _{absolutelynothing}in the use of_{natural trigonometric functions} to_prevent their

intro-duction _early in the mathematical _experience of a _{boy, except} academic tradition.

The

author has

made

use of this

mathe-matical tool_{with upper}

_grammar

_{gradeboys with} lesseffort

_upon

their_partin_masteringthe_principlesthan

_{was expended}

in master-ingsquareroot.

The

easewith

which

roof_{framingproblems}lend themselvestosolution

_by

theuseof_{natural trigonometric functions}

and

the readinesswith

which

_problems

_may

be_{generalizedthereby} has

emboldened

theauthorto

make

useofitinatextas_elementary as this.

No

_previous knowledge of _trigonometry is _presupposed,

the

_Appendix

_providesalltheinformation_requiredforthe solution

of

_any

_problemgiven herein. 7

Should a_reader,becauseoflackof timeorfor

_any

other cause, notcaretoconsider

more

thanroof_framingof the_{square cornered} building, he will find a complete treatise in Chapter III without referencetosolutionsotherthan

_by

common

arithmetic.

_Appendix

TV

offers a still

more

_{abbreviated approach} to _{both square}

and

octagonal roofframing.

The

greatestgoodin_{studyingthe chapter}

on

''

Estimating"will

come

_only

when

each student is_{provided with a} set of_plans

and

specifications completely drawn, as

_by

a _practicing architect.

Plans

and

specifications, such as will serve the purpose,

can

be

purchasedatsmall cost

from

architecturalcompanies, shouldlocal

architects be _{unwilling toprovide}setsfor theschools.

Also, there

must

be provided for each student, catalogs of lumber

and

millwork _{specifications}

and

_prices.

These

can be obtained

from

mail order

lumber

and

millwork companies.

As

a

rule,local

lumber

and

millwork companiesare glad toprovide such data,butit

must

beina

form

complete,

and

readilyaccessibleto

be

ofthe greatestvalue.

IRA S. GRIFFITH. COLUMBIA, MISSOURI,

CONTENTS

CHAPTER

I.

FOUNDATIONS

13

I. _Laying out; 2. Grade line; 3. _Excavation; 4.

Founda-tions; footings; 5. Foundation materials; 6. Forms for

con-crete walls; 7. Waterproofing; 8. Basementframes.

CHAPTER

II.

MAIN

FRAME

27

9. Methods of framing superstructure; 10. Sills and girders;

II. Bridging; 12. Trimmers and headers; 13. Walls and

partitions;joistsandroughfloors; 14. Openingsinframework.

CHAPTER

III.

ROOF

FRAME:

SQUARE CORNERED

BUILDING

45

15. Roofframing; 16. Framing the

common

rafter;laying out the _plumb cut; 17. _{Finding the length} of a

common

rafter; 18. _Layingoffa

common

rafter seat cutand endcut. 19. _Ridge

piece; 20. Hip andvalleyrafter; 21. Framinghipandvalley

rafters; 22. Side orcheek cutof hip or valleyrafter; 23.

Deter-mininglength of hip or valley rafter; 24. _Laying off seatcut

and endcutof_hip rafter; 25. Reductionof_{hip or valleylength}

becauseof ridge piece; 26. _Backing a _hip rafter; 27. _Valley

rafters; 28. Framing jack rafters; plumb cut; side cut; 29.

Lengthsof jacks.

CHAPTER

IV.

ROOF

FRAME:

ANY

POLYGON

....

69

30. _{Tangents; miter} cuts of plate; 31. _Octagonal roofs; 32.

Common

rafter for _plate of _any number of sides; 33.

Hip andvalleyrafters for_octagonand_{other polygons;} 34. Plumb

cut ofoctagonalandotherpolygonalhipsandvalleys; 35. Side or cheekcuts ofhip or valleyrafters,anypolygon; 36. Rafter lengthsof octagonalandother polygonalhips andvalleys; 37. Reductionsin lengthsfor_king-post; 38. Seat cutand endcutof octagonal and other polygonal hips and valleys; 39. _Backing octagonal and other hips; 40. _Framing octagonal and other polygonaljacks; 41. Side cut of_octagonaland_{other polygonal}

jacks; 42. Lengths of _octagonal and other polygonal jacks; 9

43. Framingbymeansofaprotractor; 44. _Translating fram-ingproblemsfromprotractor toframing squareandvice versa;

45. Framing anoctagon bay; 46. _Framingaroof ofonepitch to anotherof_{different pitch;} 47. _Framingroof of uneven_pitch;

48. _Decks;chimneyopenings.

CHAPTER

V.

EXTERIOR

COVERING

AND

FINISH

...

95

49. Sheathing; 50. _Scaffolding; 51. _Cornice; 52. Raked

mouldings; 53. Shingling; 54. Shingling hips and valleys;

55. Finishing exterior walls; 56. Setting window and door frames; 57. _Siding.

CHAPTER

VI.

INTERIOR

FINISH 115

58. Lathing; grounds; 59. _{Interior walls;} 60. Stair building; porchsteps; 61. Risersandtreads; 62. Porches; 63. Interior

finish; 64. Setting door jambs; 65. Fitting window sash;

66. Placingdoor,window, andother_trim; 67. Hangingdoors;

68. Fitting a door; 69. _{Hinging a} door; 70. Fitting locks;

71. Laying and scrapingfloors; 72. Doorand windowframes;

73. Woodworkinmasonrystructures.

CHAPTER

VII.

ESTIMATING

'. 142

74. Methodsof_estimating; 75. Tablefor_estimatingby cubic-foot unit; 76. _Grading rules; 77. _{Estimating lumber}

quan-tities; 78. Estimating millwork quantities; 79. _Example of

form for bill of _materials; 80. _Estimating labor costs; 81. Estimatingquantities of nails; 82. _Exampleof form for car-pentrycosts; 83. Totalbuilding costsbypercentages.

APPENDIX

158

I. Natural trigonometric functions; formulae deduced. Solution of righttriangles, (brief)

II. Tableofnatural functions(fordegrees only). Interpolation.

III. Usefultables.

Fractional equivalentsfordecimalvalues.

Wood

and machinescrewsizes.

Length andnumberofnails.

Wirebrads.

Boardmeasuretable.

Strengthofmaterials. Stressesforstructuraltimbers. Contentsofbrickwalls.

11 LVc Shortcuts to roofframing.

Directionsfor Griffith's_FramingTables, V. Estimating. Excavations. Masonry. Slate. Plaster. Painting. BibliographyofReferences

CARPENTRY

CHAPTER

I

FOUNDATIONS

1. _Laying out Foundations.

In

most communities

it is

customary

forthe_carpenterto

be

_present

and

toassistthe

mason

in the _laying out of the foundations.

Where

_{buildings are large}

and

_important, this

work

is

done

_{by an}

_engineer with

a

steel _tape

and

a

surveyor's

in-strument, Fig. 1. This

instru-ment

is

known

as

a

builder's transit,

and

consistsof

a

tripod

upon which

rests

a

small

tele-scope with crossed hair wires within,

by means

of

which

the observer

_may

fix the line of sight very accurately.

A

cir-cular dial contains

a

magnetic needle

which

enables the fixed dialto

be

setwith reference to the true north

and

south line ofthe observer. After thefixed dialhas

been

adjusted, the

tele-scope

may

be

swung

to_{the right} or the left until the circular

graduations indicate that it

points in the directionwanted,

after

which

stakes

_may

be set. _Fig.1. Transit

14

A

level

_upon

the telescope enables the observer to sight grades or levels;

a

helper carryingthe leveling rod, Fig.2.

Fig.

3 shows a more

common

instrument. Thisis

an

architect's Y-level

and

differs

from

the other in thatit isless

com-plete. It has

no

attachment for measuring vertical angles. This is not serious, however, since the builder seldom needs such

an

attach-ment, the level _{being the}

most

essential part. Y-levels are

made

both with

and

without

_compass

attachments.

Upon

ordinaryresidence

work

a

surveyoris

_employed

to locate

lot lines.

Once

these lines are

located the builderisable to locatethebuilding lines

by

measurement.

_Suppose

it is desired to locate

a

building

by

means

of theside lot line: ₍₁₎

Measure from

theside lot _{line, along} the front

and

along the

back

lot_lines,

a

distance equal to that

which

it isdesired the houseshall

holdrelativetothelotsideline. Drivestakeshere. (2)

While

_sighting

from one

of these stakes to the other,

have an

assistant locate

two

other stakes in the line of sight,adistanceapart sufficientto_{guarantee the placing}

of the cross-lines for the

back

and

front of the house without restaking these,

A-B,

Fig. 4.

The

process of

layingout lines fora houseisalmost identical withthat used in _laying out

a

rectangle

on a

drawing board.

(3)

Having

located alineof indefinite_lengthforoneside ofthe house,a secondlineof indefinite_{length,preferably} forthe frontofthe_building,

_may

next belocated.

To

do

Fig-.2 this, first locate

a

front corner stake

upon

the first line

Leveling

streetline.

_Having

located

and

driveninthis stake,

A

,Fig.4,drive

a

nailin_{the top}ofthe staketo

more

_{accurately locate}thiscorner.

If

an

instrumentisavailableitwill

be

locatedover this stake

and

thefront line

A-C,

Fig. 4,located

by

laying itoff at

90

_degrees

from

the side line _alreadylocated. If

no

instrumentis_available,

thefrontline

_may

be

laid offat rightangles to

A-B

by

holding

a

framing squareattheir intersection. This_angleshouldbeverified

by

the

6-8-10 method.

This consists in _measuring

from

the

Fig.4. BatterBoards

intersection at

A

_{along one}line

a

distance of

6

feet

and

_sticking

a

pinin thelineatthat point;

a

pencil

mark

may

be

used

when

the cordis white.

In

a

similar

_{manner, measure}

off

8

feet_{along the}

other line

and

then

measure

the

_hypothenuse

ofthe _{triangle so} formed. It should

measure

10 feet. If it does not, the front building line

must

be

shifted until it does. (4)

With

these

two

lines_{located, theremaining}

two

lines

_may

be

located

_by

measure-ment

from

them, the nail of stake

A

_giving the _{starting point.} Before this is _{attempted, however, the} batter boards should

be

placed. Batter boards are variously constructed.

Those

shown

are

common

_types.

_They

should_{be placed}freeofthefoundation proposed

by

atleast

3

or

4

feet. (5) Test thesquareness of the whole _lay-out

_by

_{measuring thediagonals}

A-D

and

B-C.

Ifthe building lay-outis _{square thediagonals}shouldbe_equal. If _they

arenotequal,shiftthe cords at

C

_{and D,}

_{retainingtheir parallelism,}

16

saw

kerfsshould be

made

inthe batterboards

where

the cords are placed.

These

kerfs willpermit the cords being

removed and

re-placedwithoutfurther measuring.

2.

Grade

Line.

A

_properly

drawn

set of _plans will

show

both the present lay of the

_{ground upon which}

the buildingisto beerected

and

the

new

_gradeline

which

isto beestablishedafter

Fig. 5. TakingSightswithY-Lcvel

the _building is _completed.

The

most

convenient

method

of

determining old grade lines

and

of _establishing

new

ones is

_by

means

of the_{transit, Fig. 1,} orthe_{Y-level, Figs.}3

and

5,withthe rod, Fig.2.

Both

instruments_operate

_upon

the

same

_{principle in} grade work.

The

telescope is set level

and

_sights taken thruit

to _{the target}

_upon

the rod.

The

_readingof the _{target'sposition}

upon

therod

_compared

with _{the height}of _{the telescope}

above

the

base, usually the street walk, determines the difference in grade

of_{that particular placing}of the _target.

convenient place

and

level the dial. (2)

Having

determined the height of theinstrument

above

some

predeterminedbase, suchas thestreet walk, swing the telescope

about

and,

making

allowance

for the difference in level as

_{shown by}

the _{drawings, place}

suc-cessively stakes at each corner of the building with the required

level

marked

thereon.

As

a rule, the

mason

has his

own

Y-level

and

usesit_freelyasthe wallis_{constructed, especially}

where

levels

are tobe maintainedas_{the layers}of_{material are placed.}

Fig.6. _{Leveling withStraight-edge}

In asimilar

manner

theearth_{grade aboutthe building}

_may

be

located, stakesbeing driveninto the

ground

at_frequentintervals

and

the

amount

of "fill

"

or reduction indicated thereon.

Grade

levels are established _{usually only} after the builders are _thru, exceptthat the

mason

will

have

the_gradeindicatedfor

him

where

the wall

above

the _grade is to be _{differently finished}

from

that below.

Where

no

_surveyor's level is at _hand, the

mason

or carpenter

will secure the levels

_{by means}

of

a

straight-edge of

some

14 feet

in_length.

A

common

levelis_placed

_upon

_{this'plank as}

shown

in

IS

successivelevelings,

a

grade

may

becarried quiteadistance with-out verygreatvariations.

3. Excavations. Excavations should be

made

enough

larger

than the_{proposed foundation} that the

mason

_may

have

room

to wieldhistrowelin_{pointing the}

outer joints,

and

for

water-proofing.

An

extra footof ex-cavation

_upon

each side will

usually be required.

All foundations

must

be carried well below the frost line. Excavations should be

made

_accordingly. GRAVEL TILL DRAIN TIL' CONCRETE

WALL

WATERPROOFING IMEnrjLOOR, rOOTlliG:

Fig. 7. FoundationDetail

4. _Foundations;Footings. Because ofthe _tendencyof

a_{building to} settle _unevenly,

due

to variations in the

strength of the supporting ground or the _{unequal weight placed}

_upon

this _ground,

found-ations

must

be constructed of

some

non-yielding material such as brick or stone,

and

of such thickness

and

so

bonded

that the weightofthe building

may

be evenly fetributed.

The

thicknessofwallwill

_depend

_iponthe _weight to be sup-ported

and upon

the character of thesoil.

Unless rock_{or gravel} is_{encountered, every foundation should}

have

a

_{footing, Fig.} 7.

The amount

of footing used is usually twice the thickness of the foundation wall. In brick walls this

footing drawsinto the wall

_by

_"stepped"

courses _{of brick,} each layer beingnarrower than the one _{just preceding.}

For

_ordinary residence

work

with _ordinarysoil conditionsa 10- or 12-inch wall

resting

upon

a footing 2 feet wide

and

8 or 10 inches _deep will suffice.

A

safefooting for supporting posts of6"

x6"

yellow pine, for

most

soils,will be 10inchesdeep

by

18inches square. Partition

walls _carrying

no

unusual load

need

not

be

over

8

inches in thickness.

20

in _filling the voids or spaces

between

the

members

has little strength as

compared

withthatofthe stone or brickitself. This bondingissecured

by

placing thebrick or stone so thattheyshall overlap one another, both along the faces of the wall

and

across thewall.

Bricks laid with their _lengths in the

same

direction as that

of the wall are

known

asstretchers; thoselaid withtheirlengths across the wall are

known

as headers, Fig. 8.

The manner

of

THRU

STONE

RANDOM

RUBBLE

-3TONE BOHD ERJCK BACKING

METAL

COUR5ED

A5HLAR

FACING'

BROKEN

ASHLAR

ROCKFACED ASHLAR,

22

Inrubble

work

the stones arerough

and unhewn.

They

must

belaid

upon a good bed

of stiff mortar with their stratifications in

a

horizontal position. Otherwise, the face of the wall

might

"peel"

from

theeffects of frost

and

moisture,

making an

unsightly as well as a

weaker

wall.

The

term

"

ashlar" refers to

a

wall

X4'S

WIRI-Fig. 12.

"Form"

forConcrete

buildedof stones_havingfinished faces.

When

eitherrubble

work

or ashlar is laid

_up

in courses it is

known

as coursed rubble or coursed ashlar.

When

the horizontal _joints are not continuous the wallis

known

as

random

rubble orbrokenashlar.

Not

_infrequently

a

wall will be constructed with

an

ashlar facing attached to

a

brick_backing

_{by means}

ofmetal bonds. In such a_wall,the faced_ashlar,unless

more

than 8inchesinthickness

and

well

bonded

into the wall, should not be considered in

esti-matingthe strengthofthewall.

should becarried

_up

_{as nearly as possible at the}

same

levels. In both brick

and

stone walls the corners are

run

up

with stepped courses, thecorners being

plumbed

as thewalliscarried _upward.

A

lineisthenstretched

between

thecorners_and,layer

_by

_layer,the

rest ofthe wallfilledin.

No

_{corner should,ordinarily,}

be

carried

more than

3 feet

above

the rest of thewall.

In

the case of un-coursedstone

work

the wallis leveled_{every 15} to 18 inches inits

height.

6.

Forms

for Concrete Walls.

The

economical _building of

formsforconcrete wallsis

a

matterofimportancein building

con-struction. _Fig. 12

shows

a

_type of

form

suitable forfoundation work.

Such

forms should

be

made

of semi-seasoned stock.

Thoroly

seasoned stock will

_warp

_badly

when

the

wet

concreteis

placed. Spruce,

Norway

pine, etc., are better

woods

to usethan

hard or_Georgiapine.

For

ordinary foundation

work

1-inch boards

may

be

used, the studs _{being placed not over}

2

feet apart.

These

studs

may

be

assisted_materiallyin_holdingtheforms_{in position,}

_by

wires_placed as in _{Fig. 12,}

and

_by

_{props placed} against the dirt wall of the excavation.

In_{placing the concrete}a_{4-inch layer}islaid

and

then''

spaded"

or

"worked"

well into _place, a

"wet mix"

_being used.

The

smoothness of the _resulting faces is increased

_by

an

additional spadingofthe mixture

_away

from

theform.

A

_good

_spadingtool

is

made by

_{straightening}out

an

_{ordinarygarden}hoe. Thisallows

the

cement

and

mortartoflownexttothe

form

and

holdthis_place

while the_{fillingproceeds.}

Where

formsare_{placedto give} finished walls,that is,walls to

which

no

_plaster is to be_{applied, they should be aligned}with

no

greater variationthan

%"

from

thelines specified.

Forms

should

be

allowed to

remain

until the concrete will

24

There

is

no

limitto_{the ingenuity}one

_may

make

useofin

form

building.

The

illustration givenis merelysuggestive.

7. Waterproofing.

The

extent to

which a

wall should be waterproofed will

depend

upon

the location of the building.

Foundations near running water

must

naturallybebetter protected

Fig. 13. CellarFramewithSash

thanthose inwelldrainedlocations. Fig.7illustrates

a

treatment whichwill_{prove quite}safe foralmostall localities.

The

exterior face of the walliscovered with_{several layers}of

_asphaltum

ortar.

By

coating thetopofthe footing

and

the_topoftheconcretefloor just before the finishfloor of

cement

is placed, little water will enter.

A

drain tile carried about thehouse as

shown

in _Fig. 7, especiallyif _gravelis _{placed against the wall}

above

it, will

meet

everyemergency.

There

areother

_ways

of_{waterproofing}

basement

walls,but this

is_{typical of}the external wall treatments.

In

monolithic

construc-tion_{waterproofing}

_may

be

secured

_by

_{appropriate additions to the} mixtureof_{waterproofing materials}suchas slackedlime, justbefore

&.

Basement

Frames. Fig. 13illustratesonesuccessful

form

of

basement

window

frame

_{construction,}with sash. In this_type

thesash is _hinged to the _topof the _frame,

and

a catch or button at the

bottom

of the frame secures the sash

when

closed.

The

,UG5

TEMPORARY

5TAY

vCELLAR

\riOOR,

Fig.14. BasementDoor Frame

constructionis such as tobest shutout

wind

and

water

when

the sashisclosed.

Fig. 14 illustrates a

basement

door frame.

Frames

such as this,

and

the

window

frameof Fig. 13,are

made

of

heavy

stock

and

are

known

as_plankframes.

Basement

frames areheldin_place

_{by means}

of

wooden

blocks nailedtothesides ofthe frame, as well as

by

the projecting "lugs"

of the frame itself.

The

frame is set

_{and plumbed}

_by

the

car-penter assoonas the

mason

has preparedthesill.

Fig. 14

shows

a

26

wall. _Fig. 15indicatesthe positionof

_plumb

and

level in the set-ting ofa frame.

The

edgesofa door frameare

''

sighted

"

forwind.

Where

it is necessary to attach frames orother

woodwork

to

brick walls, it is _customary to

have

the

mason

insert

wooden

Fig.15. _{Plumbing andLeveling} CellarFrame

"bricks" as the wall is constructed.

Wooden

bricks are of the

same

sizeasotherbricks,

and

shouldbeconstructedwiththeedge whichis tobelaid

back

inthe wall thickerthan_{the front edge, so} thatadovetailedeffectissecured.

CHAPTER

MAIN FRAME

-9.

Methods

of

_Framing

the Superstructure. In the early

days

when

lumber

was

plentiful, houses

and

barns

were framed

in

what

is

known

as "full

frame."

Such

frames con-sistedof

_{heavy and}

solid

timbers

mortised

and

tenoned

and

_pinned

to-gether, Figs. 16

and

17.

With

the_{growingscarcity} of

lumber

the

"half

frame"

_{of Fig.}18

became

common.

This

latter

type,itwillbeseen,

makes

less use of

_heavy

timbers

and

wooden

_pins,

and

more

use of _planks

and

nails.

_To-day

the vast

majority

of _buildings,

where

wood

is the

ma-terial_{used, are constructed}

by

what

is

known

as

"balloon

_framing"

in houses

_{and "plank}

fram-ing" in barns, Figs. 19

and

20. In view of _this,

attention will bedirected

4x6GI

"10JOIST

'

Fig.16. FullFrameHouse 27

28

to balloon framing only.

One who

is able to frame a house

should have notrouble _{with plank barn} framing,

where

drawings

show

the details.

6*6

Fig. 17. HeavyTimber Barn

It

must

be understood, too, that there are quite a varietyof

ways

of_framing

a

balloon

and

_{a plank}frame. It willbe _possible inthis _chapter to treat of but one _type.

A

_mastery

of this one type should enable the studentto

work

out _{other types,} with

10. Sills

and

Girders. In _Fig. 21 will be found illustrated

three types of

box

sill construction.

Whatever

the sill _{used, care}

must

be takento so_planthatmice

_may

not

have

freeaccess to the

Fig. 18. Half-Frame House Fig. 19. BalloonFrameHouse various parts of the _building. If the sill does not inhibit, then

blocksshould be spiked

between

thestuds.

Such

blocks serve as

The

bed

plate of the

box

sillshould

be

selected

from

stock with straight

edges. Inthe framingof joists, plan so that the crowning edges shall

be

up

when

in _position,

and

in _placing the joists see

that the

most

crowning are in the middle of

a

room. _Joistsare fastened to their sills as in Fig. 21.

Fig. 22-a illustrates

a

built

up

girder,

and

the

manner

of _framing the

joists to it.

Three

2"x

10"'s with

a

2"x4"

at-tached to each side, the

whole _{thoroly spiked}

to-gether,

form

the girder.

The

advantage

of this

type ofgirderlies mainly

in the fact that it leaves the

headroom

of

a

base-ment

clear,

which

is not the case in the_type

shown

inFig.22-b. This second type is

somewhat

easier to_frame,

and

is therefore greatly used

where

the

32

It is better where furnace stacks

must

be _placed in a _partition aboveit.

First floor joists, like second floor joists

and

studs, should be

Fig.22-a. Fig. 22-b.

Girder_Types

spaced 16 inches

from

center to center, beginning at one side or endofa room.

Not

to

make

such_provision

would

cause

a

waste

in lathing,since the lath are

all4 feet_{in length,}

a

multiple

of 16 inches.

_Any

remainder

aftersuch_{a spacing should be} allowedto

come

at the sideor

&

end

of theroom.

11. Bridging.

To

add

to

Sthe

carrying

power

of floor

joists, bridging is cut in

be-^MK^^""

1-^! ^^^aal

tween

them

as

shown

in _Fig.

23.

For

_ordinary dwellings

l"x

3" stock will serve.

O?

large work, stock

two

inches thick should be

made

use of.

more

than 8feet_apart.

A

miter-box,setatthe_{appropriateangle,}

may

be used_{in cutting bridging,}all_{the piecesbeing cut}atone time withthe_exceptionof those forthe

odd

_spacingsatthesideor

end

of

a

room.

A

more

common

practiceis totake

a

_{piece of stock,} and, after_cutting a bevel

on

one _{end, place} it as in _i'ig.

23

with

SPACING

STAY

GIRDER

Fig. 24. Layingoff_{a Stay}

the beveled

end above

the_{lower edge}of the _{joist against}

which

it rests,

a

distance slightly inexcess of the thicknessof the stock; then

saw

as indicated, sawingvertically

and

alongthejoist.

Before _{placing bridging,}the_joist

must

be

_spaced

and

_properly

fastenedin place. Thisis

done

_by

_placing

a

pieceofstock,1"

x

6" or

_2"x4",

as in _Fig. 24.

With

a

try^quare,

mark

thelocations

of the _joists. This

board

_may

then

be

transferred to thecenter

ofthe

room

and

the_joiststhere_{spaced according}tothe_marks,

and

placing the spacing board in the center of the

room

and having

a second person sight the joists for straightness while the first

party places

them

as directed

and

'tacks them. This tacking

consists in _driving the nails

only partially in, leaving the heads_project

_enough

that they

may

later be

withdrawn

with

a

claw

hammer.

Still another

method

is_{to lay}off the

_"stay"

by

measurement

withthe fram-ingsquaresothatit_corresponds

with _{the spacings} of the _joists attheside walls.

Bridging should be nailed with

two

nails at each

end

of

the piece.

12.

Trimmers

and

Head-

Fig.

26. _PlacingHeadersand Trimmers

ers. In the

_making

of stair

_{and chimney}

_openings it

becomes

necessary to support the ends of _joistsother than in the usual

manner.

Thisis

done

by

cutting in headers as in _Figs. 25,

26

and

27.

Where

the

_span

is

not

_great, such as at

an

ordinary

36

residence work, in which but one or

two

tail

beams

are to

be

carried, headers arenot doubled

and

are merely spikedin place.

Where

many

joists are to be carried, headers or trimmers, or

carryingjoists

must

bedoubled. Ironstirrups or hangers should

be used instead of _spikes in joining headers to carrying joists

where_spikes

would weaken

the carryingjoist

and would

not give

VIEADE.R TRU55ED /tRIPPLE.

-'

5ETOHEDGE.

Fig. 28-a. Fig. 28-b.

HeadersandTrimmersinWallFrame

sufficient strength to the joint.

Except

upon

long spans, tail

beams

_{are usually fastened to the} header

_by

_{spiking only.}

On

longspans theyshouldbeframedtotheheaderas_joistsare

framed

toagirder,a 2"

x4"

being spiked firmly to theheaderasa_support. In determining the

amount

of _{space to allow}for

head

room

in framing about a wellhole fora _stair, determine the run

and

rise ofthestairfromthe_plan

and

elevation,

and

then plan toallow at

least6'_6", measured from the _{proposed nosing} line of the treads

up

to the_proposed location of the _{trimmer, or carrying joist,} or header, as the case

may

be,at theceilinglevel, Fig. 121.

The

term

"header"

is alsoused _{to designate the studding, or}

joistinthe caseofdouble doors, placed horizontallyover

window

and

door_{openings,Fig. 28. Studding}cutinbelow

window

open-Fig.29. HeadersandTrimmersinWallP'rame

STOPS

-SICOttD TLOOR_ JOIST

Fig. 30. StudandJoistPatterns

ingsformsthestool,also

known

asheader.

The

illustration

shows

the

manner

of _framingfor_openings of differentwidths.

A

small

single

window

may

requirebut onethicknessof2

"

x4".

A

medium

theopeningisratherlarge, asinthe caseof double dooropenings, two_{joists will}beset

on

edge overtheopeningas header.

13. Walls

and

Partitions; Joists

and

Rough

Floors.

A

study

of Figs. 16, 17, 18, 19, 20

and

29 shouldgive

an

understandingof

theessential

members

of

the

framed

wall of a

building,

and

their rela-tions one toanother.

Whether

side walls shall

be

framed

and

raised before the rough or false floor of thefirst

storyis laid will

_depend

upon

the _type of sill

construction

made

useof.

In _laying off _studs, joists, etc.,apatternisfirstframed.

These

patterns areafterward used in_{the building}

and

are therefore counted in with the total

number

of _pieces to be framed.

To

_{these patterns, stops}

and

Fig. 31. MarkingJoistsfrom Pattern

Fig. 32-a. Fig. 32-b.

Corner PostTypes

Fig.32-c.

fencesare attached near the

two

ends

and

at _{the middle, Fig. 30.}

The

other studs or _joists of similar dimensions are laid off one

at a time

_by

_{superimposing} these _patterns

_{and marking}

about

them

with_{pencil, Fig. 31.}

MAIN

Ribband

orribbonboards

and

plates arelaidoff

_by

_placing

them

alongside the"layout"forthe studs

made

_upon

thesills,

and

tran-scribing the

marks

totheribbandboard

and

plate

by means

of

try-square

and

pencil.

Sometimes

ribband boards

and

plates arelaid

off

_by

measurement, as aresills.

Corner

_{posts are} constructedfirst

and

placed. Fig. 32-a

shows

a

section of

a

corner _post

which

has

much

to

com-mend

it. _Fig. 32-b

illustrates

a

more

common

_type

of

construction.

The

most

_serious

objec-tion to this _type is

the fact that the

post

must

be furred

after the lather _{has placed}'the lath

_upon

one

side of the room. Corner_{posts are}

_{plumbed and}

_stayedin

two

_{directions, afterbeing}

raised, Fig. 33. Either 2"x 4" or 1"x 6" stockwill

be

used for stays.

With

thecorner postsset, the ribbandboards are placed.

Where

the _span is _{too long} for

_any

_{available length} of ribband

board, in layingouttheribband boardsprovision

must

be

made

for

their

_"breaking"

_joints

_upon

studs.

These

studs will be raised immediatelyafterthe corner_posts,theribbandboard attached to corner _post

and

stud, after

which

the stud will be

_{plumbed and}

stayed, Fig. 34. Studs are

framed

before being raised so that ribband boards

_may

be"let into"

them

as

shown

in Fig. 34.

Sec-ond and

third_{floor joists will}be notched to_slip overtheseboards

40

and

willbe_{spiked to the studs}inaddition.

Remaining

studs are placedoneatatime,one

man

setting

up and

nailingthe foot while

JOIST

Fig. 34. SideWallStayed

another fastens theribband board to thestud at the secondfloor line,Fig. 35.

With

the _completion of the _{raising of} the

two

outside walls whicharetobearthe_{joistends, the}middle_partition, should there be_{one, paralleling} these walls shonld b^

framed

and

raised.

A

MAIN

slightly different procedure

from

that just described is followed, thatis,insteadof raisingone studata time the

whole

partitionis

framed and

nailed together

upon

the floor,

even

to the cutting

in of headers, etc.

When

a section such as the

number

of

men

available can raise is _{ready, the}

same

is _raised,

and

_stayed after being plumbed.

The

studs of

parti-tions are

framed

but one _{story high}

and

_"plated" at such a _{height that} second floor _joists

_may

be _placed thereon in splicing. Just as far as possible first

and

second floor joists

should be spaced to restone _directly

above

another

and

in line with the supporting studsof_{partitions so that}

furnace stacks

_may

be _{placed with}

ease. If _joists rest

_upon

_partition

plates

and

not directly

above

studs, a doubleplate

must

be

made

use of.

Having

placed the second floor

joists, the studs at the ends of the

house

_may

beset_up. Theirlocations

will be

marked

_upon

sill

and

_upon

second floor _joist

which

is to be placedat the

end

of the house. This

marking

is best

done

by

placing the

joist

upon

the sill

and

_transcribing

the

marks

laidout

_upon

the sill to the _joist, after

which

it is to be raisedinto_place.

Double

_plates will next be framed.

_They

should break

_upon

studs

and

be

marked

_by

_{transcribing the}

marks

forthe studs

from

thesills.

At

_{the corners the plates}willbe

framed

with butt_joints,

thesecondset_lappingoverthe_joints

_{made by}

thefirst_plate. Fig. 35. SettingupStudsand

Next, the sustaining middle partition of the second story is raised as

was

that of the first _story.

The

attic _{floor joists} are placed aswerethosefor thesecond floor.

All walls

and

partitionsare

now

"linedup," thatis,

any

irregu-larities are taken out

by

additional stays.

False or _rough floorsare laid in the variousstories

where

not_{already placed,} bridging being placed

and

openings for

stairs

and chimneys

framed.

Such

floors

are laid either _diagonally or _straight across the _joists.

The

diagonalflooris

considered_{better, Fig. 27.}

14.

_Openings

in

Framework.

Studs

inoutside walls aresetwithoutreference

to_openingsfordoors

and

windows.

Such

openingsare cut

and

headers

and

stools placedafter the walls are

up

and

ready

for sheathing.

The

seeming waste

oc-casioned

_by

this

method

is _{slight since}

the cut-out material is available for

headings, etc.

Most

_carpenters

make

a _{story pole} to be used in laying off

window

and

door heights incutting out

studs. Thisis _nothing

more

than a _piece of 1"

x2"

or 1"

x3"

stock with _{the heights} of the _openings

from

the _rough floor or from the_joists, where the _rough flooris not laid,

marked

plainly thereon. This _pole is _{placed alongside the} stud to be cut

and

the

mark

transcribed

from

_poleto stud.

Beginners are frequently troubled in _determining the _proper opening,even

when

thesizeofthe

window

is_specified. In_general,

carpenters plan to

have

the studs

on

either side of

an

opening,

either dooror_window, so set that the outer _edges of the exterior

(O

casings will break

_upon

their centers.

Windows

are _specified

_by

thewidth

and

_{heightof their glass}

and

the

number

of divisionsor

lights,

width

always being specified first.

The

distribution of excess

measurement due

to the_meetingrail, top

and

bottom

rails, side railsorstiles is

shown

in _{Fig. 36.} Rail

and

stile widths

and

sash thicknesses will _vary

from

those _given

_{when any}

_{very great}

DOOR

3'x7'

3-7

Fig. 37. Framing Wall Openings

increase in size of

window

is

made.

Manufacturers of sash

and

doors provide catalogs in

which

stocksizesarelisted.

Estimate

an

openingvertically, Fig. 36, thus: Sill, 2";

sub-sill,

where frame

is

made

withone, 1";

bottom

rail,

from

edge to

bottom

of rabbet, 3"; glassinlowersash, 34";meetingrail,

from

rabbet _{to rabbet, 1"; glass}in

_upper

_{sash,34"; top} rail,2"; space

for

head

_jamb

and

_lugs of side _jambs,

2"

or 3"; total, 79".

A

carpenter

would

say,

"Add

11" to the glass

measurement

to get vertical _height

between

stool

and

header."

Window

sasheswith

muntins

require

an

addition of

_^"

for each muntin.

The

thick-nesses ofheader

and

stool

must

be considered in addition to the

measurement

_just

mentioned

when

studs aresawed, Fig. 37.

44

glass, 28";width of stiles,

from

rabbeted edge

to outer edge, 4"; width of casings, 8"; total 40", distance

from

center of stud to centerof stud.

_Comparing

this with thewidth_{of glass}it willbe seen that thedifferenceis 12".

A

carpenter, therefore,

makes

use ofa_generalrule:

Add

10"tothe_glass

measurement

to get distance

between

studs,

where

a 4" or 4J/2" casing is used with this

typeof

window

frame.

For

the 3'x

T

door, Figs.

37

and

38,estimate the open-ing as follows: Heightof_door,

7'; allowance for roughfloor,

%";

finish floor,

%";

thres-5X" tr, 3/

Fig. 38. ThresholdDetail

hold, 5

/

s "

to

_%"\

head

jamb

fnmsnrtooR

and

space for lugs of side .-ROUGH TLOOR.

jambSj 2 "

to 3"; total

from

joist,

may

be7'5".

For

the width of _opening

estimate:

Width

of _{door, 3';}

widthof casings,at

4^"

each, 9"; total _spacing of studs center to center,3'9". Distance be-tween studs willbe 3'7". This will leave _space

_enough

to _put

the doubling studs

on

each side

between

header

and

floor. Since

locations of_openings in the

main

frame, both

window

and

door, are dimensioned to the centers of _{the openings,} it is easiest in

layingoff to estimate

from

the center each

_way

rather than to estimate totalwidth.

After these_openingsare

_made,

theframe of the house

_may

be coveredwith_{sheathing, or the}roof

_may

_{be framed; both}ordersof

CHAPTER

III

ROOF

FRAME: SQUARE CORNERED

BUILDINGS

15.

Roof

Framing.

The

problem

of _framing the various

members

of a roof is not a difficult _{one provided} the _underlying

principlesare understood,

and

dependence placed

upon

this under-standing rather than

upon mere knowledge

of

what

_figures touse

upon

the_squaretoget thecuts,without

knowing

why

those_figures

GABLE HIP

SHED

GAMBREL

Fig. 39. Roof Types

are used.

An

effort willbe

made

in thistreatment to indicatethe

"why."

In _Fig. 39 areillustrated_{four types}of roof. _{Figs. 40,41,}

and

42 illustrate the rafter forms

and

the

names

of the various cuts tobe

made

in_framingthe

members

_{to place.}

The

common

rafter, itwillbe_seen, hasthreecuts

_plumb

_{or ridgecut,}seator heelor platecut,

and end

cut.

The

hip, valley,

and

jack

have

four cuts each;asidecut orcheekcutis_possessed

_by

eachinadditiontothe three cuts_belonging to the

common

rafter.

Before

_any

rafter_{can be framed,} the rise

and

run ofthe

com-mon

rafter, inotherwords, the pitchofthe_roof,

must

be

known.

In _{roof framing, the}

"run"

of a rafter

when

in place is the horizontal distance

measured from

the extreme

end

of the seat toapoint directlybelowthe ridge

end

of therafter,Fig. 43.

The

RIDGE PIECE

COMMON RAFTER

HIP RATTER.

VALLEYRATTER. HIPJACK RATTER.

VALLEYJACK. CRIPPLE JACK PLATE TAIL -31DECUT PLUMB CUT END CUT CVT

Fig. 40. RoofDetails

HTP RATTER

Fig. 41. PlanofRoofRafters

"rise" isthevertical distance

from

the ridge

end

of the rafterto thelevel of theseat.

The

"pitch" of

a

rooforrafteristheratio oftheriseoftheraftertothe_spanorwhole widthofthe_building.

ROOF

SQUARE

BUILDINGS

meanings

they

may

be used _{to designate}

"unit"

lengths. In allsuch cases 12" ofrun ofthe

common

rafter is

assumed

as the

base,

and

the other unit lengths or constants are

computed from

this constant.

The

numerical values of these constants will

be

computed

asthe

_development

of _{the subject}ofroof_framing

makes

theiruse necessarv.

Fig. 42. RaisingtheRafters

It willbe noted_{in Fig.} 44 that the constant of_{run, or} 12",is

taken alongthe_tongue

and

therise_perfootof_{run along}theblade

of _{the square.} Itisnot essentialthat this orderbe_followed; the beginnerwill_generallyfinditeasiertovisualize his_{work, however,}

if_{he keeps} the _tongueforeitherrise _{or run,}

and

the bladeforthe opposite.

There

areoccasions

when

the reverse orderis _necessary

no

matter

which form

is_{followed, so that}itisunwiseto insist

_upon

only oneway.

The

variationin _terminologyinroof_framingis_{so general that}

com-a

=

_RISE

C=LEWGTH

A=AtiGLEOr

INCLiriATlOM

Fig. 43. Run,Rise_{and Length}

Fig.44. UnitLengthof

Common

Rafter

mon.

Hereafter

an

effort will be

made

to confine the text to the_following:

_plumb

_cut,seatcut,

end

cut, side cut.

The

valuetoa_beginnerofa_carefully

made

_planofarooftobe framed with _necessary data such as rafter lengths

and

positions indicated thereon,cannotbe_{too stronglyemphasized.} Architects not infrequently prepare elaborate

and

_{complete framingplans}for

ROOF FRAME: SQUARE

prepare plans before attempting to

frame

the same. Fig. 43 illustrates

a

framing plan ready for the placing thereon of the necessary data, suchas

measurements

along the platefor_spacing

the rafters, lengthsof rafters,ridgepieces, etc.

16.

_Framing

the

Common

Rafter; Laying outthe

Plumb

Cut.

-

_While

_{in thisdiscussion the}

plumb

cutisfirst_described,itshould

<TTT<

L

LEIiGTHOF

_TAIL^X

_\>LEttGTH

OF RATTER.

5mon

orOPERATOR,

46siT10ttOF OPERATOR

Fig. 45-a-b. Layingoff

Common

Rafter

be understood that itis _{equally as}convenient

and

more

common

among

carpentersto_beginthe_framingofthe

members

of_{a square}

corneredroofframe withthe

end

and

seatcuts. _{In framing}other than a square cornered roof it is

somewhat

more

convenient to

beginwith the

plumb

cut.

The method

of _framing of the

common

rafteris the

same

for

all_buildings,whether_{the buildings}

have

foursidesor

more

orless. (1)Placetheframing squareasinFig.45-b,taking12

"on

thetongue as the run,

and upon

the blade the riseininches_per foot ofrun.

Keep

these

numbers

against the crowning, or

what

is to

become

the _topedgeof therafter,

and

scribealongthe blade. Thisgives

50

the

plumb

cut. Occasionallyacarpenterwillbe found

who

frames

to

a

centerline ratherthan thetop edgeof a rafter.

Figs. 45,46

and

47 illustrate theproper position of theworker relative to his work.

Such

aposition will

seem

awkward

to the

Fig. 46. Position inLayingoffPlumb Cut whenLaidoffbeforeSeatCut

beginnerbut he should learn to visualize his

work

while in this position that the efficiency of framing

may

not be reduced thru

the

awkward

_positionfirst_likelytobe assumed.

17.

To

Find the

Length

ofa

Common

Rafter. First

Method:

The

theoretic length

of

a

rafter is indicated

_by

the centerlinesin_Figs. 45-a

and

48. In _estimating the

total _length of stock for a

rafter_having

a

tail, the run

of tail _{or length} of lookout

must

be considered.

The

pitches

most

com-monly

usedarethehalf,third,

and

_quarter.

From

an

examination_{of Fig.}43 itwillbe seen that the lengthofa

common

rafteristhe_hypotenuseofa_{right triangle}

whose

_legsare therise

and

therunoftheroof.

The

_problem,then,

Fig. 47. LayingoffPlumbCutwhen

ROOF FRAME: SQUARE

BUILDINGS

of_{finding the length}of a

common

rafter

when

the rise

and

run

are

known

is_merelythatofsolving theequationc2

=

a?-\-b2.

Practical carpenters

would

not consider it

_economy

to take timetosolve forrafter_{lengths in}this

_manner,

for_everyvariation

in rise or run

would

necessitate

a

rather_longsolution. _Instead,

they

have

discovered that for _every foot of run of

a

rafter the

OF

TAIL

Fig. 48. RafterLength

length of therafter increases proportionately, the ratio of riseto run remainingthe_same,Fig.44.

With

a

table, therefore,in

which

the length of rafterfor eachfoot of _{run, for}eachof the

common

pitches is _{given, the length} of rafter for

_any

_{given pitch} can be found

_by

_{merely multiplying}the _{constant given}

_by

the

amount

of

runfor _{that particular}rafter.

Fig.

49 shows

such

a

table

worked

out for a rather extended

number

_{of pitches.}

From

thistableitwillbeseen that the

number

totakeas a constantfortherunis_12",

and

thattheriseininches per foot of run is taken

_upon

the other

member

of _{the framing} square.

A

jackrafteraswill

be

illustrated laterisbut

a

shortened

common

_{rafter,therefore,}

what

issaidofthe

common

rafterisalso

true ofthe_jack rafter.

The

_{jack, however, has}

an

additionalcut

which

will be discussed in another section.

52 Example:

Determinethe length ofacommonrafter ofahouse witha 25'_span anda quarter pitch,withouttail.

TABLE,TOR

COMMON

ANI>JACKRATTERS

SQUARE t OCTAGONAL ROOT

/

^

/

g

/ _pj

SQUARE

common

or jackrafter_lengths, (1)consider therunas12" taken

on

the_tongue; (2) select

upon

theblade alongits _{outer edge}theinch

mark

which

represents theriseof the roof_perfoot ofrun_required to give the pitch specified; (3) the

number

directly

below

this

zo

PER.TOOT

RArTEK.5 II16

SHEATHINGIIMVALLtY

22 2

I I I ill III III ill ll ii

Fig. 50. Framing SquareDetail

mark, reading across the blade in the space

marked

"

Length

of

Common

Rafter

Per

Foot

of

Run"

_{gives the lengthper} foot for

that particularriseor_pitch.

As

a

check for rafter _{length computations, the following}

pro-cedureis_{suggested: Selecting the}runas12"

on

thetongue

and

the

riseininches_perfootofrun

on

_{the blade, place}one square

upon

an-other as

shown

in_{Fig. 51,using}thatside ofthesquare dividedinto inches

and

twelfths.

Do

notuse the

end

of_{the blade, the}

rounded

corner

makes

it_{impossible to secure theaccuracy}

demanded.

Ex-treme accuracyis_requirediftheconstantistobe usedforrafters of

considerable length of run.

Read

the _diagonal length

between

the

numbers

_{representing the}run

and

rise.

Read

the

whole

num-berof inches asfeet,

and

the fractions asinches,

and

takeoff

any

fractional remainder

_{upon a}

_{very sharp pointed pair} of dividers.

Read

this_{divider spacing}

_by

means

ofthehundredthsscale

on

the framingsquare.

The

resultshould, ifthe

work

is_{veryaccurately}

done, be the

same

as that obtained

_by

computation from

the

tables,eventothehundredthsplace decimal.

Upon

ordinary

work

where

_{g ^at accuracy} is not_{required carpenters} sometimes

deter-mine

thisconstantfora givenpitch

by

placing the framing square as in

54

blade the rise,

marking

along both tongue

and

blade.

The

dis-tancebetween these

marks

is then read

on

a square placed along

the edge.

Second Method:

In

determiningrafterlength,

an

equally

com-mon

practiceisto lay theframing squareas

is

shown

_{in Fig. 45-a.}

While

in this _position

the seat cut is scribed,

cf. Section _18,

and

also

ashort_sharplinescribed along theother

member

of the_squareat the top edge of therafter.

The

square is

moved

_along,

using the

same

numbers,

and

another

advance

mark

scribed. This op-erationis _repeated just

as

_many

times as there arefeetin therunofthe

common

rafter.

With

_{a span} of 24' the _operation

would

be repeated 12 times.

Shouldtherun not

_happen

tobeinevenfeet, thesquare

would

be placed as

_many

times as there

were

full feet in the run. In additionit

would

be

advanced

thatfractional_part

which

the frac-tion oftherun

was

of 12".

For

example,in

a

runof 12'_7",witha

roof of3< pitch,thesquare

would

be

advanced

12 timesusing the

number

12

on

the _tongue

and

6

on

the blade. Inaddition tothis

the square

would

be

advanced

using

T

7

? of 12"or7"

on

the_tongue

and

T2? of 6" or 83/2"

n

the blade.

As

these

numbers do

not

allow

_enough

of the_squaretorest

on

the rafterto give

a

full line,

assoonas theadvancelimit of rafter_lengthisindicated the_square

may

be

moved

up,using the setof

numbers

first_{used, that}is12"

FRAME:

SQUARE

BUILDINGS

and

6".

On

common

rafters, this last operationis _simplified

_by

noting that the fractional run, divided

by

12, times 12, always equalsitself.

The

final_{position of the square, therefore,}

_may

be obtained

_by

_{simply sliding} the

_member,

used in laying out the

last full foot line

which

parallels the seat cut,

an

additional

dis-Fig. 52. Layingout Rafter

tance_equal to the fractional foot of total _{run, Fig.} 44.

The

tail

lengthisobtained_{similarly,Fig.} 44.

18. _Layingoff

Common

RafterSeat

Cut

and

End

Cut. First

Method:

_Having

determined the rafter_{length as directed in} Sec. 17,first_{method, (1) lay}offthis_lengthalongthe_{upper edge}

begin-ningatthe

plumb

cut.

The

whole

number

of feet is

more

_safely

"taken

off"

_by

means

ofa_pole

marked

infeet,

and

of

good

length.

56

foot. (2)Placesquareas at"b,"Fig. 52,standingas inFig.45-b,

and

scribea

_plumb

lineas indicated at1-2, Fig. 52. (3)

From

the

point 1, Fig. 52,

measure

along the line

marked

1-2

a

distance

equal to one-halfthatof 1-2.

The

distance1-3

may

beincreased ordecreased

somewhat

when

an

extremepitch

makes

itadvisable.

As

arule thisshould be

2^"

to 3". (4) Placethe squareasatc,

Fig. 52,withtheedgeofthe_{tongueresting}

on

3

and

scribealinefor

&

THICKNESSOF _-j

RIDGE ^DIAGONALOF

HIP-RIDGE

Fig. 53. Independent RafterTail

THEORETIC LENGTH

OFRIDGE REAL

LEttGTH-Fig. 54. Lengthof_RidgePiece

the_{seat cut,}as 3-4.

These

last

marks

give thebird's

mouth

joint

whichis tofitover theplate.

While

_many

carpenters allow

end

cuttingof therafter tailsto wait until the rafters are set in place so that they

may

be lined

and

cut while in _position, certain kinds of

work

_permit the ends

tobecut at the

same

time the remainderof the rafteris framed. Inthis latter

method

the_squareis_{placed as inFig.}

44

and

₍₅₎ the

end

cutscribed.

The

_pointof cutoff

on

the tailis determined in

the

same manner

asthatusedin_determiningrafter_{length, the}run

ofthetail_{being considered}

and

thetail_lengthbeing

measured from

the point1, Fig. 52.

Where

a corniceis of unusual width, tails _{are usually} framed

independentof the rafters

and

arethen _{spiked to the} ends of the