Total load, 20 pounds per square foot.

Size of Joist.

Dist. on Centres.

Hemlock.

White Pine.

Spruce or

Norway

Pine.

Oregon or Texas Pine.

Georgia Pine.

Ins.

Ft.

Ins.

Ft

Ins.

Ft

Ins.

Ft.

Ins.

Ft.

Ins.

2x4

12

9

3

9

5

10

I

10

5

11

2

2x4

16

8

5

8

6

9

1

9

5

10

1

2x6

12

14

0

14

1

15

1

15

7

16

8

2x6

16

12

8

12

10

13

8

14

2

15

2

2x8

12

18

8

18

10

20

1

20

9

22

4

2x8

16

17

0

17

2

18

4

18

11

20

5

2x8

20

15

9

15

10

17

0

17

6

18

10

Total load, 24 pounds per square foot.

2x10

12

22

0

22

2

23

8

24

5

26

4

2x10

16

20

0

20

2

21

7

22

3

23

10

2x10

20

18

6

18

8

20

0

20

7

22

2

2x12

12

26

5

26

8

28

5

29

4

31

7

2x12

16

24

0

24

2

25

10

26

8

28

8

2x12

20

22

3

22

5

24

0

24

8

26

8

In some localities framing lumber is often sawn a little scant in both thickness and depth, and wherever such is the case a corresponding reduction must be made in the safe span. A reduction should also be made for any cutting of the joists that may be required.

No allowance has been made for partitions, and when they are to be supported by the floor joists additional joist should be used or the span reduced according to the relative direction or position of the partition and joists.

Tables VIII to XII, inclusive, were computed by the formula for stiffness, on the assumption that the deflection should not exceed 1/30 of an inch per foot of span. Tables XIII and XIV were computed by the formula for strength.

The spans given in these tables come within the requirements of the New York, Buffalo and Denver building laws, and tables VIII, X, XI, XII and XIV comply with the Chicago law, but to comply with the Boston law a reduction of about one-sixth must be made from the spans given.

By Georgia pine is meant the long-leaf, yellow or hard fine.