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Elementary principles of carpentry ... : ; to which is added an essay on the nature and properies of timber / by Thomas Tredgold
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262

TABLES OF SCANTLINGS.

No. II.

Table of the Scantlings of Binding Joists, of Yellow Fir, for different Bearings , from 5 to20 feet, when the distance from middle to middle is G feet. See Sect. III. art. 149 and150.

Length ofbearing infeet.

Depth

6 inches.

Depth

7 inches.

Depth

8 inches.

Depth

9 inches.

Depth

10 inches.

Depth

11 inches.

Depth

12 inches.

Length ofbearing infeet.

Breadth

Breadth

Breadth

Breadth

Breadth

Breadth

in inches.

in inches.

in inches.

in inches.

in inches.

in inches.

5

4f

3

2

5

6

6|

4

3

2

6

7

s*

4

H

2

7

8

7

51

H

8

9

H

4i

3*

9

10

s

H

4

3

Qi

10

11

Depth

Depth

Depth

6f

5

3f

3

11

12

13 inches.

14 inches.

15 inches.

8

6

H

H

12

J.25

Breadth

Breadth

Breadth

7

H

4

13

14

in inches.

in inches.

in inches.

8

5f

4y

14

15

4

q.i

2 J

9

6f

5i

15

16

H

03

o 4

10]

7i

6

16

17

Hi

°2

8J

6-f

17

18

5f

4f

4

10

7i

18

19

6*

KX

,J 2

4}

8i

19

20

7i

6

4f

n

29

To find the scantling for a binding joist for any bearing, look in either the right or left hand columnof the table for the bearing in feet, and opposite the length of bearing, and under some one of thedepths at the head of the columns, will be found the breadth required. Thus, if it be required to findthe scantling for a binding joist for a 10 feet bearing, 9 inches is a depth that would be suited to thefloor; then opposite 10 feet, in one of the side columns, and under 9 inches at the head of one of themiddle columns, we find 5| inches, the breadth required. If 8 inches had been fixed upon for the depth,it would have required 8 inches in breadth to be equally as stiff as one 9 by 5|. If the bearing be 19feet, and 13 inches should be of convenient depth, then opposite 19 in the side columns, and underdepth 13 inches, we find 6| inches the breadth required.

40/2

This table is calculated by the rule ~ = b ; where l is the length in feet; and d the depth, and bthe breadth, each in inches.