Orioku system

In this ease, the rafters' tie beams sit directly on top of the columns and the cavc girders run on top of the tie beams. The stepped tenon of the column is notched a few millimeters shorter than shown in the diagrams to avoid having the girder accidentally snagged by it. The Orioku system results in a lower ceiling height than the Kyoro. The Kyoro system is more flexible because rafters and tic beams do not have to be supported at the same location as the columns.

From left to right: rafter, girder, column, tic beam

Ranbo* oeam(t>e beam)

f Elevation;

i

Classical Elevations

o The column is set on a groundsill.

0 The tie beam is set onto the column (column head: stepped tenon).

o The column is set on a groundsill.

0 The tie beam is set onto the column (column head: stepped tenon).

Tee Tie Roof Beam

lie beam fcrjce(t* rod)

Internal root bcaro

Ptfnposl

T* beamflewver)

Purlin Splice

Tie beam connector

(Koya daimochi)

Sometimes tic beams must be spliced and tied to an internal roof beam network. The unique characteristic of this joint is that neither the lower tie beam nor the upper tic beam suffer a reduction in section at their splicing point.Thc diagram displays the arrangement of such a joint with provision for a purlin post on top of the assembly. Generally purlin posts arc evenly distributed. They are not always located at the connection of tie beams and roof beams. The dowels used to position the tic beams over each other arc usually 30mm wide and arc always drilled in vertically instead of normal to the internal faces of the joint.

lie beam fcrjce(t* rod)

Ptfnposl

Internal root bcaro

T* beamflewver)

lo*tr wewj

L.

; r cs

*

a y

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"T

Plan.;

bottom Tie beam (lower)

Elevation S

Internal roof beam bottom Tie beam (lower)

Internal roof beam

How Does Meth Look Like
O Internal roof beam
Internal Rafter Images

© The upper tie beam sits on the lower tie beam. A purlin post is added to the assembly.

CONNECTING JOINT 12

Hip rafter joint

(Yosemune no sumi)

Three kinds of hip rafter joint with five sun pitch will be introduced (one sun is one tenth of a foot). All of these joints have common characteristics. The roof rafters (including corner's cave brackets) arc normal to each other and all of them have the same pitch. (1) Tee-shaped girder joint

Precisely manufactured tenon and mortise (goya hozo sashi) arc nccessary to make this joint. The hip rafter (sumigi) sits on top of the longer girder. An eccentric tenon and mortise serves to assemble the eavc girders.

From left to right: Corner's eave brackets, girder (A), girder (B). hip rafter

—-*~-Root r^ter p*tct> (5 a/i ptctO ——1 • —Hip ratter p»tcti ---*—Half roof ratter ptcfr(2 5 sld pitch)

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Pljr>. sop view ' S

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--1-1

Hip rafter

Hip Rafter Joint Girders

Deration

Deration ligl s y

Girder IB)

Hip rafter

Uli LMLJ U5_J Corner's eave brackets

O Arrangement of the girders

0 Girder (A) is inserted into girder (B) and a wedge is pounded in (rabbeted tenon and mortise).

O The corner's eave brackets are installed.

■BH^HHiHaBaH

Layout (1)

A carpcntcr square is used to layout the dimensions on site. One side of the carpenter square has a 1:1 scale. The other side has a 1^2 scale.

Figure a) shows how to layout the dimensions for the rafter sockets on the cave girders. On girder I, a line is extended down from the "togcM (point A) with the same pitch as the rafters' (5 sun pitch). This line intersects girder I on the top face and outer face at point B and point C respectively. Two lines, parallel to the center line of the girder, arc laved out from point B and point C to the intersection with girder II at point G and point D. Line CD is extremely important. It is called the "Kuchiwaki" line. From point D another line is laved out with the same pitch as the roof rafter's. This line intersects the end face of girder II at point E. Line EF is drawn across the face, parallel to the top surfaces of the girders. The planes STUV and WXYZ represent the bottom faces of the grooves destined to receive the rafters.

The layout for the hip rafter is displayed on figure b). We have just explained how point B and C were crcated from the "toge" (point A) on girder I. In the same fashion, point B' and C are established on girder II. The Kuchiwaki line from point C and its counterpart on the top surface from point B', are drawn along girder II. Line B' - intersects the inner face of girder I at point H (line B'H is parallel to girder's II center line RQ just as line BG is parallel to girder's I center line PQ).

Girder System Layout

(a) Girders layout with notches for rafters (including corner eave brackets)

(c) Layout for the lateral pitch of the top surface of the hip rafter

Eave Corners

(d) Layout of the intersection of a rafter corner eave bracket) with tho hip rafter

Rafter or comer eave bracket

Hip Rafter Layout Tools
(b) Hip rafter layout

Rafter or comer eave bracket

(d) Layout of the intersection of a rafter corner eave bracket) with tho hip rafter

(c) Layout for the lateral pitch of the top surface of the hip rafter

A new line, GH, is layed out on top of the intersection of the two girders. Two more points, J and K are set one half of the hip rafter width apart from the center point H and point G. The sides of the hip rafter arc projected down on the top surfaces to form lines X)' and line KK'. On those lines, point J' and K' arc extended to the intersection with the outer face of girder II at point 1. Line IN is drawn at one half the roof rafter's pitch (2.5 suns pitch) on the outer face of girder II. sloping down from point I. The extension of line JJ' and line KK' give us point L and point M, located on the outer face of girder II. From point L and M, two vertical lines are drawn down the face of girder II. The intersection of these lines with line IN produces point N and point O respectively. We now have all of the lines necessary to cut out the groove destined to receive the hip rafter. The bottom surface of the groove is included within J'K'ON. (J'K'rwidth of hip rafter)

Figure c) demonstrates how to layout the lateral pitch on the top surface of the hip rafter. The plane BCD on figure c) is parallel to 0,8,0 in figure b). The lateral pitch of the top surface is given by the ratio of EF/BF on figure c). Assume AC=h

CB=2h, AH—y5h, CD=2/2h, AD=3h, BD=2h. AB,-BE,=AEI, BD*-BE2

AB2—EiD*=AE2—ED*= (AD—ED)2—ED2=9h2—6h-ED ED=yh

zFF'D=90°, ZFDF*=45° FF'=FD *-^=h( = FD) BF'=BD-FD=2h—h

BF - /BF^l FF2=/2h BF2+EF2=^h2=BE2 consequently /.BFE-90° —%|-h/(,/2h)

Figure d) demonstrates how to layout the cutting plane for the intersection of a roof rafter (corner cave brackets included) with the hip rafter. HIJ on figure c) is made parallel to 0,B,G in figure b). GIJ on figure c) is made parallel to 02B:G in figure b). The surfaces GHJ and GKN are on the side of the rafter (corner eave brackets included). Their pitch are GI/IJ and KN/KL respectively.

¿GIJ—HIJ=90* ZGHI= zGHJ—904 ZlHJ = ZlJH=45* Assume IJ—a

111=a IIJ=/2a tan UGJH) =1/2^2 GH=ya GI2=GII2+III2=ja2

consequently

Assume KL

GL-consequently KN/KL

Finally, figure c) shows the layout of the Iwttom of the hip rafter where it contacts the girder. XYZ in figure e) is made parallel to OtB,G in figure b). ZYD and XYD contact the face of the girder. The pitch is FX/FD. Let the hip rafter width be W.

2 272~T72

FD=AX

Hip Rafter Joints
(e> Layout of the bottom of the hip rafter at the intersection with the girder

(2) Cross-shaped girder joint

In practice the girders join together in a Tee-shaped assembly. Afterward, a ---e---Roof ratter p»icti(5 su^ ptcti)

"nose" is added to the shorter girder, giving -----r9htr ^

the joint the appearance of a cross. ---&---Half roof rtftrr p.tdv<?5 a* p!d>)

Traditional Japanese Architecture System

Elevator»

Girder (A)

Elevator»

Girder (A)

Japanese Housed Dovetail Joint

On top. from left to right: Girder B. girder nose, girder A. hip rafter On the bottom: rafters

Rafter Layout Hip Roof
Hip rafter
Hip Joint Architecture

Q

» »

L ■ •

--J «O

\

1

W \ i\ s \

-

• • • • • • •

o £

Girder

Pljn. top

Pljn. top in

Elevation

Plan; bottom viw

Elegit on

Rafter

Architectural Girders

O Arrangement of girders A and B and of the girder nose

Japanese Girder

© Girder B is inserted into girder A 'housed dovetail).

Girder rv^

O Arrangement of girders A and B and of the girder nose

© Girder B is inserted into girder A 'housed dovetail).

Dovetail Rafters ConnectionsJapanese Housed Dovetail Joint

The joint is completed by installing the rafters.

Japanese Housed Dovetail Joint

The joint is completed by installing the rafters.

Layout(2)

Note: The general layout discussed for the Tee-shaped girder joint will be omitted for the next two joints. Only new concepts need be introduced.

The layout of the end of the hip rafter is displayed in diagram b). The pitch of the hip rafter, called nagesuini pitch, depends on the roof rafters pitch (5 sun pitch) and is assumed perpendicular to the end surfaces of the hip rafters. The plan PRS is parallel to 0,B:G in figure b). The plan ORS is parallel to 0,B,G in figure b). OQS and OPS lay within the vertical face of the hip rafter. The values required arc OQ, OS and TV respectively.

f) Layout for cutting the hip rafter's end

The surface OQS is normal to the fascia boards.

Assume OP=h

¿POR-ZPRQ PQ=PR * 2=4h 0Q 5h since z OSR = z TVS with OR/RS=y5/2. = W

(3) Bevelled halving (ncjigumi)

The cave girders cross on top of each other in a formation called hip corner. To balance the strength along both axis, the girder sections are carved out by an equal amount. This concept of joining is called bevelled halving. The girders overlap at their intersection. The stepped tenon of the corner column slides through the intersection of the girders and extend beyond it, ready to receive the hip rafter. The hip rafter joins onto a rafter column set back from the corner column.

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Woodworking Tools and Installation Tips

Woodworking Tools and Installation Tips

There are a lot of things that either needs to be repaired, or put together when youre a homeowner. If youre a new homeowner, and have just gotten out of apartment style living, you might want to take this list with you to the hardware store. From remolding jobs to putting together furniture you can use these 5 power tools to get your stuff together. Dont forget too that youll need a few extra tools for other jobs around the house.

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