Span.

Tie-beam A.

Queen- posts Q.

Principal rafters P.

Straining beam S.

Braces B.

Purlins C.

Small rafters r.

feet.

inches.

inches,

inches.

inches.

inches

inches.

inches.

32

10

x

4 1/2

4 1/2

x

4

5

x

41/2

6 3/4

x

4 1/2

3 3/4

x

2 1/4

8

x

4 3/4

3 1/2

x

2

34

10

x

5

5

x

3 1/2

5

x

5

6 3/4

x

5

4

x

2 1/3

8 1/4

x

5

3 3/4

x

2

36

10 1/2

x

5

5

x

4

5

x

5 3/4

7

x

5

4 1/4

x

2 1/2

8 1/2

x

5

4

x

2

38

10

x

6

6

x

3 3/4

6

x

6

7 1/4

x

6

4 1/2

x

2 1/2

8 1/2

x

5

4

x

2

40

11

x

6

6

x

4

6

x

6

8

x

6

4 1/2

x

2 1/2

8 3/4

x

5

4 1/4

x

2

42

11 1/2

x

6

6

x

4 1/2

6 1/4

x

6

8 1/4

x

6

4 1/2

x

2 3/4

8 3/4

x

5 1/4

4 1/2

x

2

44

12

x

6

6

x

5

6 1/2

x

6

8 1/2

x

6

4 1/2

x

3

9

x

5

4 3/4

x

2

46

12 1/2

x

6

6

x

5 1/2

7

x

6

9

x

6

4 3/4

x

3

9

x

5 1/2

5

x

2

Pitch of the roof about 27 degrees, covering slate, and timber Baltic pine. The letters refer to the engraving, as in the Table above.

The scantlings in these Tables are calculated by the rules in Sect. IV. The smallest scantlings have been taken that ought to be used for good Riga or Memel timber; soft and inferior kinds of timber will require them to be larger.

No. VII. Table Of Scantlings For Roofs Of From 46 To 60 Feet Span, To Design, Plate III.; Trusses 10 Feet Apart. See Sect. IV., Art. 231

Span.

Tie-beam A.

Queen-posis Q.

Posts D.

Principal rafters P

Straining beam S.

Braces B.

Purlins C.

Small rafters r.

feet.

inches.

inches.

inches.

inches.

inches.

inches.

inches.

inches.

48

11 1/2

x

6

6

x

5 3/4

6

x

2 1/4

7 1/2

x

8

8 1/4

x

6

4 1/2

x

2 3/4

8 1/2

x

5

4

x

2

50

12

x

6

6

x

6 1/4

6

x

2 1/2

8 1/2

x

6

8 1/2

x

6

4 1/2

x

2 3/4

8 3/4

x

5

4 1/4

x

2

52

12

x

64 1/2

6

x

6 3/4

6

x

2 3/4

9 1/4

x

6

8 3/4

x

6

4 3/4

x

2 3/4

8 3/4

x

5 1/4

4 1/4

x

2

54

12

x

7

7

x

6 1/4

7

x

2 1/4

8 1/4

x

7

9

x

6

4 3/4

x

2 3/4

8 3/4

x

5 1/4

4 1/2

x

2

56

12

x

8

7

x

6 3/4

7

x

2 1/2

8 1/2

x

7

9 1/4

x

6

5

x

2 3/4

8 3/4

x

5 1/4

4 1/2

x

2

58

12

x

8 1/2

7

x

7 1/4

7

x

2 3/4

8 3/4

x

7

9 1/2

x

7

5

x

2 3/4

9

x

5 1/4

4 3/4

x

2

60

12

x

9

7 1/2

x

7

7

x

3

9

x

7

10

x

7

5

x

3

9

x

5 1/2

4 3/4

x

2

No. VIII. Table Of Scantlings For Roofs, From 60 To 90 Feet Span, To Design, Plate IV.; Trusses 10 Feet Apart. See Sect. IV, Arts. 232 And 233

Span.

Tie-beam A.

Queen-posts Q.

Posts D,D.

Principal rafters P.

Straining beam S.

Kingpost k.

Braces B.

Purlins C.

Small rafters r.

feet.

inches.

inches.

inches.

inches.

inches.

inches.

inches.

inches.

inches.

65

15

x

10 1/2

8

x

7

5

x

3

8

x

7 1/2

10 1/2

x

8

5

x

3

5

x

3 1/2

8 1/4

x

5

4

x

2

70

15

x

11 3/4

9

x

6 1/2

5

x

3 1/2

9

x

7

10 1/2

x

9

5

x

3 1/2

5

x

3 1/4

8 1/2

x

5

4 1/4

x

2

75

15

x

13 3/4

9

x

7 1/2

5

x

4

9

x

8

11 1/4

x

9

5

x

4

5

x

4 1/2

8 3/4

x

5

4 1/2

x

2

80

16

x

13

9

x

9

6

x

4

10

x

9

12

x

9

6

x

4

8

x

3 1/2

8 3/4

x

5 1/4

4 1/2

x

2

85

16

x

13 1/2

9 1/2

x

9

6

x

4 1/2

11.

x

9

12 3/4

x

9

6

x

4 1/2

6

x

4

9

x

5 1/4

4 3/4

x

2

90

16

x

14

10

x

9 3/4

6

x

4 1/2

11.

x

10

13

x

10

6

x

4 1/2

6

x

4

9

x

5 1/2

5

x

2

In these Tables the pitch of the roof is supposed to be about 27 degrees, the covering slate, and the timber to be good Riga or Memel pine. Inferior timber will require to be of larger dimensions, but the addition of one-fourth of an inch to each dimension will be sufficient for any difference in quality, except it be knotty timber. The letters refer to the parts on the engravings.

No. IX. Table Of Scantlings For Roofs, From 55 To 65 Feet Span-, To Design, Plate V.; Trusses 10 Feet Apart. See Sect. IV., Art. 234

Span.

Tie-beam A.

Queen-posts q.

Principal rafters P.

Straining beam S.

Posts D.

Braces B.

feet.

inches.

inches.

inches.

inches.

inches.

inches.

55

12

x

8

8

x

6

8

x

8

10

x

8

6

x

4

6

x

4

60

12

x

9

9

x

6

9

x

7

10

x

9

6

x

4 1/2

6

x

4 1/2

65

13

x

9 1/2

9 1/2

x

6 1/2

9 1/2

x

8

11

x

9 1/2

6

x

5

6

x

5

In roofs of this design, and between 55 and 65 feet span, the purlins may be 9 inches by 5 inches, and common rafters 5 inches by 2 inches.

No. X. Table Of Scantlings For Roofs, From 70 To 80 Feet Span, To Design. Plate VI.; Trusses 10 Feet Apart. See Sect. IV., Art. 235

Span.

Tie-beam A.

Queen-posts Q.

Principal rafters P.

Straining beam S.

feet.

inches.

inches.

inches.

inches.

70

15

x

11 1/2

9 1/2

x

8

13

x

9 1/2

12

x

9 1/2

Scantlings of the upper parts may be obtained from Table No. V.

75

15

x

14

10

x

8 1/2

13 1/2

x

10

12

x

10

80

16

x

13

10 1/2

x

9

14

x

10 1/2

13

x

10 1/2

85

16

x

14 1/2

11

x

10

14 1/2

x

11

13

x

11

No. XI. Table Of Scantlings For Roofs, From 20 To 32 Feet Span, To Design, Plate VIII.; Trusses 10 Feet Apart. See Sect. IV., Art. 237

Span.

Tie-beam.

Curved rib.

Suspending Pieces.

Purlins.

Common rafters.

No. of Pairs.

Scantlings of each Piece.

feet.

inches.

inches.

incites.

inches.

20

8

x

4

4

x

4

3

4

x

2

8

x

5

3 1/2

x

2

24

8

x

4

4 3/4

x

4

3

4

x

2

8

x

5

4

x

2

28

8

x

5

5 1/2

x

5

3

4

x

2 1/4

8 1/2

x

5

4 1/2

x

2

30

8 1/2

x

5

6

x

5

3

4

x

2 1/4

8 1/2

x

5

4 3/4

x

2

32

9

x

5 1/2

6

x

5 1/2

3

4

x

2 1/2

8 1/2

x

5

5

x

2

The pitch, etc, the same as in the preceding Tables.

No. XII. Table Of Scantlings For Roofs, From 35 To 100 Feet Span, To Design, Fig. 1, Plate VII.; Trusses 10 Feet Apart. See Sect. IV, Art. 236

Span.

Tie-beam.

Curved rib.

Suspending Pieces.

No.of

Pairs.

Scantling of each Piece.

feet.

inches.

inches.

inches.

35

11

x

6

6

x

6

4

4

x

2 1/2

Purlins, 9x5 inches.

40

11

x

6

7

x

6

4

4

x

2 3/4

45

11

x

6 1/2

8

x

6 1/2

5

4

x

2 3/4

50

11

x

7

9

x

7

5

4

x

3

55

11

x

7

10

x

7

6

4

x

3

60

11

x

8

10

x

8

6

4

x

3 1/4

65

11

x

9

10

x

9

7

4

x

3 1/4

70

11

x

9 1/2

11

x

9 1/2

7

4 1/2

x

3 1/4

Small rafters, 5x2 inches.

75

11

x

10

11

x

10

8

4 1/2

x

3 1/4

80

12

x

10

12

x

10

9

4 1/2

x

3 1/4

85

12

x

11

12 1/2

x

11

9

4 1/2

x

3 1/2

90

12

x

11

14

x

11

10

5

x

3 1/4

95

12

x

12

14

x

12

11

5

x

3 1/2

100

12

x

12

15

x

12

11

5

x

4

The pitch is supposed to be about 27 degrees, the covering slate, and the timber good Riga or Memel pine.