All of the trusses thus far described have horizontal tie-beams,

Table II. - Dimensions For Lattice Trusses Of First Quality White Pine Or Spruce. To Support A Gravel Roof And Plastered Ceiling. Allowing 20 Pounds Per Square Foot For Snow

Span.

Spacing of trusses.

Height out to out.

No. of spaces.

Size of bottom chord.

Size of top chord.

End braces.

Inner braces.

Bolts in joints 1-5.

See

Fig. 25.

Ft.

Ft.

Ft.

Ins.

Inch.

40........

12......

5

6

16

4-2

X

6

4-2

X

6

2

X

6

2

X

6

2 - 1

7

2

12

4-2

X

6

4-2

X

6

14........

5

7

16

4-2

X

6

4-2

X

8

2

X

6

2

X

6

3 - 7/8

7

3

12

4-2

X

6

4-2

X

8

16........

5

8

16

4-2

X

8

4-2

X

8

2

X

8

2

X

6

3-1

7

4

12

4-2

X

8

4-2

X

8

50..........

12.........

6

8

16

4-2

X

8

4-2

X

8

2

X

10

2

X

8

3 - 1

and

8

8

12

4-2

X

8

4-2

X

8

2

X

6

14........

6

8

16

4-2

X

8

4-2

X

8

2

x

10

2

X

8

3 - 1 1/8

and

8

8

12

4-2

X

8

4-2

X

8

2

X

6

16..........

6

9

16

4-2

X

8

4-2

X

10

2

X

10

2

X

8

3 - 1 1/8

and

8

8

12

4 - 2

X

8

4-2

X

8

2

X

6

60...........

12......

8

4

16

4-2

X

10

4-2

X

10

2

X

10

2

X

8

3 - 1 1/8

10

10

12

4-2

X

10

4-2

X

10

14.........

8

4

16

4-2

X

10

4-2

X

10

2

X

10

2

X

8

3 - 1 1/8

10

10

12

4-2

X

10

4-2

X

10

16.........

8

4

16

4-2

X

10

4-2

X

10

2

X

10

2

X

8

3 - 1 1/4

10

10

12

4-2

X

10

4-2

X

10

70.........

14........

9

5

16

4-2

X

10

4-2

X

12

2

X

10

2

X

8

1 - 2 1/4

12

4

12

4-2

X

10

4-2

X

10

16.....

9

5

16

4-2

X

10

4-2

X

12

2

X

10

2

X

8

1 - 2 3/8

12

4

12

4-2

X

10

4-2

X

10

18.........

9

6

16

4 - 9,

X

10

4-2

X

12

2

X

10

2

X

8

1 - 2 1/2

12

6

12

4-2

X

10

4-2

X

12

80.......

14......

11

0

16

4-2

X

12

4-2

X

12

2

X

10

2

X

8

1 - 2 3/4

14

0

12

4 - 2

X

12

4-2

X

12

16.....

11

2

16

4-2

X

14

4-2

X

14

2

X

12

2

X

10

1 - 3

and

14

0

12

4-2

X

12

4-2

X

12

2

X

8

18......

11

2

16

4-2

X

14

4-2

X

14

2

X

12

2

X

10

1 - 3

and

14

1

12

4-2

X

12

4-2

X

14

2

X

8

Uprights at end same size as end braces.

which are the most desirable as well as the most economical whenever the conditions will permit.

In roofing churches, public halls, etc., a raised ceiling is often desired in order to give greater height to the room, without increasing the height of the walls.