Renovation-Headquarters Banner
Home
Site Search

Rafters Sizes, Low Slope (Over 3 in 12 or less) With No Finished Ceiling - 30 psf Live Load, - 16 inch spacing

Calculating the size of the rafters you need when building a home or an addition is not a complex situation as we have provided a group of tables that will allow you to make your selection.

Note: Always check with your local building department to ensure that your choice of rafter sizes and material meets their requirements.

Four tables are provided:

  1. High Slope (Over 3 in 12) With No Finished Ceiling - 20 psf Live Load, 7 psf Dead Load - 12 inch spacing
  2. High Slope (Over 3 in 12) With No Finished Ceiling - 20 psf Live Load, 7 psf Dead Load - 16 inch spacing
  3. Low Slope (Over 3 in 12 or less) With No Finished Ceiling - 30 psf Live Load, - 12 inch spacing
  4. Low Slope (Over 3 in 12 or less) With No Finished Ceiling - 30 psf Live Load, - 16 inch spacing
Low Slope (Over 3 in 12 or less) With No Finished Ceiling
30 psf Live Load, - 16" spacing

Species

Grade

2 X 6

2 X 8

2 X 10

2 X 12

Coast Sitka Spruce

Select structural

12' 6"

16' 6"

21' 1"

25' 7"

No. 1 & Appearance

11' 8"

15' 5"

19' 7"

23' 10"

No. 2

10' 8"

14' 1"

18' 0"

21' 11"

No. 3

8' 1"

10' 8"

13' 7"

16' 6"

Douglas Fir, Larch
(North)

Select structural
or No. 1 & Appearance

12' 9"

16' 10"

21' 6"

26' 1"

No. 2

12' 6"

16' 6"

21' 1"

25' 7"

No. 3

9' 8"

12' 8"

16' 2"

19' 8"

Eastern Hemlock-
Tamarack (North)

Select structural
or No. 1 & Appearance

11' 5"

15' 1"

19' 3"

23' 5"

No. 2

10' 10"

14' 3"

18' 3"

22' 2"

No. 3

8' 10"

11' 8"

14' 11"

18' 1"

Hem-Fir (North)

Select structural or No. 1 & Appearance

12' 0"

15' 10"

20' 2"

24' 7"

No. 2

11' 2"

14' 9"

18' 9"

22' 10"

No. 3

8' 7"

11' 4"

14' 5"

17' 7"

Ponderosa Pine

Select structural or No. 1 & Appearance

11' 2"

14' 8"

18' 9"

22' 10"

No. 2

10' 3"

13' 7"

17' 4"

21' 1"

No. 3

7' 11"

10' 5"

13' 3"

16' 2"

Red Pine

Select structural

11' 5"

15' 1"

19' 3"

23' 5"

No. 1 & Appearance

11' 2"

14' 9"

18' 9"

22' 10"

No. 2

10' 2"

13' 5"

17' 1"

20' 9"

No. 3

7' 9"

10' 2"

13' 0"

15' 9"

Spruce Pine Fir

Select structural

12' 0"

15' 10"

20' 2"

24' 7"

No. 1 & Appearance

11' 5"

15' 1"

19' 3"

23' 4"

No. 2

10' 5"

13' 9"

17' 6"

21' 4"

No. 3

7' 11"

10' 5"

13' 3"

16' 2"

Western Cedars
(North)

Select structural
or No. 1 & Appearance

10' 10"

14' 3"

18' 3"

22' 2"

No. 2

10' 5"

13' 9"

17' 6"

21' 4"

No. 3

8' 1"

10' 3"

13' 7"

16' 6"

Western White Pine

Select structural

11' 9"

15' 6"

19' 9"

24' 0"

No. 1 & Appearance

11' 2"

14' 9"

18' 9"

22' 10"

No. 2

10' 0"

13' 2"

16' 10"

20' 6"

No. 3

7' 9"

10' 2"

13' 0"

15' 9"