Joist Span Tables - Ceiling Joists

Ceiling Joist Spans for Southern Yellow Pine, Douglas Fir, and Eastern Spruce

Joist span tables - use these tables to determine lengths, sizes and spacing of ceiling joists.

Note: Ceiling joists of the first floor of a two-story structure often serve as floor joists for the second floor. If this is the case with your structure, use the Floor Joist Table to determine maximum joist length/load.

For example, the highlighted cell (below) shows that a 2" x 6" Southern Yellow Pine joist, with a grade of #2, and spaced 24" apart can have a maximum span of 10 feet - 0 inches (10-0), if you are designing your structure to support a plaster ceiling.

Joist Span Tables

Nominal Size	Spacing (o.c.)	Species and Grade of Lumber ( No Attic Storage - Drywall Ceiling)
		Southern Yellow Pine	Southern Yellow Pine	Douglas Fir	Eastern Spruce
		#1 grade (kiln dried)	#2 grade	#2 grade	Structural
2" x 4"	12	13-2	11-10	12-8	11-7
	16	11-11	10-9	11-6	10-6
	24	10-5	9-5	9-11	9-2
2" x 6"	12	20-8	18-8	19-11	18-2
	16	18-9	16-11	18-1	16-6
	24	16-4	14-2	15-7	14-5
2" x 8"	12	27-2	24-7	26-2	24-0
	16	24-8	22-4	23-10	21-9
	24	21-7	18-8	20-6	19-0
2" x 10"	12	34-8	31-4	32-9	30-7
	16	31-6	28-6	29-9	27-9
	24	27-6	23-1	26-0	24-3

Nominal Size	Spacing (o.c.)	Species and Grade of Lumber (Limited Attic Storage - Plaster Ceiling)
		Southern Yellow Pine	Southern Yellow Pine	Douglas Fir	Eastern Spruce
		#1 grade (kiln dried)	#2 grade	#2 grade	Structural
2" x 4"	12	9-1	8-3	8-9	8-0
	16	8-3	7-6	8-0	7-3
	24	7-3	6-6	7-0	6-4
2" x 6"	12	14-4	12-11	13-9	12-7
	16	13-0	11-9	12-6	11-5
	24	11-4	10-0	10-11	10-0
2" x 8"	12	18-10	17-0	18-2	16-7
	16	17-2	15-6	16-6	15-1
	24	15-0	13-2	14-5	13-2
2" x 10"	12	24-1	21-9	23-2	21-2
	16	21-10	19-9	21-1	19-3
	24	19-1	16-10	18-5	16-10

The above spans are based on American Softwood Lumber standard sizes.

** Note: The data in the tables above were obtained from Architectural Drawing and Light Construction by Edward J. Muller.

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