Plates V. to XII. are reduced copies of part of the contract drawings for some roofs recently constructed.

There is no object in describing them in detail, but it should be mentioned that Plates XI. and XII. are inserted by the kind permission of Sir Alexander Rendel, K.C.I.E., and the remaining plates by that of Messrs. Handyside and Co.

The student will derive more benefit by carefully studying these practical drawings of well-designed roofs than from representations of roofs drawn merely to illustrate the text.

Table Of Scantlings Of Iron Roofs (From Actual Practice)

Table Of Scantlings Of Iron Roofs From Actual Prac 200268

Fig. 308.

Rise, H = 3/5. Rise of Tie Rod, t = 3/45. Principals 6 feet 8 inches apart.

Span, s.

Rafter, PR.

Struts, S.

King Bolt.

Queen Bolt.

Tie Rod.

In feet

T iron.

T iron.

a.

6.

c.

d.

e.

f.

Inches.

Inches.

20

2½x2 x3/8

2 x2 x3/8

¾

3/8

..

5/8

¾

25

2¾x2½x3/8

2 x2 x3/8

7/8

¾

5/8

7/8

1

30

2¾x2½x½

2½x2½x3/8

1

¾

5/8

1

1 1/8

35

3x2¾x½

2½x2½x3/8

1

¾

¾

1

1 1/8

1¼

40

3½x3x½

2½x2½x5/8

1 1/8

7/8

¾

1 1/8

1¼

1 3/8

45

4 x3½x½

3 x3 x½

1¼

1

7/8

1 1/8

1¼

1 3/8

50

4 x3½ + 5/8

3 x3x5/8

1¾

1

7/8

1¼

1 3/8

1½

55

5 x4½x5/8

4 x4x½

1 3/8

1 1/8

1

1 3/8

1½

1 5/8

60

5 x4½x¾

4 x 4 x 5/8

1 3/8

1 1/8

1

1½

1 5/8

1¾

1 Maynard.

2 From Molesworth's Pocket Book.

Table Of Scantlings Of Iron Roofs From Actual Prac 200269Table Of Scantlings Of Iron Roofs From Actual Prac 200270Table Of Scantlings Of Iron Roofs From Actual Prac 200271Table Of Scantlings Of Iron Roofs From Actual Prac 200272Table Of Scantlings Of Iron Roofs From Actual Prac 200273Table Of Scantlings Of Iron Roofs From Actual Prac 200274Table Of Scantlings Of Iron Roofs From Actual Prac 200275Table Of Scantlings Of Iron Roofs From Actual Prac 200276