Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Maximum Floor Joist Span

No. 1 and No. 2 Grade of Douglas fir and maximum span floor joists - imperial units

Maximum floor joist span for No. 1 and No. 2 Grade of Douglas fir are indicated below. Max. dead load (weight of structure and fixed loads) 10 lbs/ft2.  Live load is weight of furniture, wind, snow and more.

  • 1 psf (lbf/ft2) = 47.88 N/m2
  • 1 ft = 0.3048 m
  • 1 in = 25.4 mm

Floor joists - maximum span

Max. Live Load 30 lbs/ft2(1436 N/m2)

Maximum Floor Joist Span, Live Load 30 lbs/ft2(1436 N/m2) (ft - in)
Nominal Size
(inches)		Joist Spacing Center to Center
(inches)
Lumber Grade
Selected StructuralNo. 1No. 2
2 x 6 12 12' - 6'" 12' - 0" 11' - 10"
16 11' - 4" 10' - 11" 10' - 9"
24 9' - 11" 9' - 7" 9' - 1"
2 x 8 12 16' - 6" 15' - 10" 15' - 7"
16 15' - 0" 14' - 5" 14' - 1"
24 13' - 1" 12' - 4" 11' - 6"
2 x 10 12 21' - 0" 20' - 3" 19' - 10"
16 19' - 1" 18' - 5" 17' - 2"
24 16' - 8" 15' - 0" 14' - 1"
2 x 12 12 25' - 7" 24' - 8" 23' - 0"
16 23' - 3" 21' - 4" 19' - 11"
24 20' - 3" 17' - 5" 16' - 3"

Max. Live Load 60 lbs/ft2(2873 N/m2)

Maximum Floor Joist Span, Live Load 60 lbs/ft2(1436 N/m2) (ft - in)
Nominal Size
(inches)		Joist Spacing Center to Center
(inches)
Lumber Grade
Selected StructuralNo. 1No. 2
2 x 8 12 13' - 1" 12' - 7" 12' - 4"
16 11' - 11" 11' - 5" 10' - 8"
24 10' - 5" 9' - 4" 8' - 8"
2 x 10 12 16' - 8" 16' - 1" 15' - 0"
16 15' - 2" 13' - 11" 13' - 0"
24 13' - 3" 11' - 4" 10' - 7"
2 x 12 12 20' - 3" 18' - 7" 17' - 5"
16 18' - 5" 16' - 1" 15' - 1"
24 15' - 10" 13' - 2" 12' - 4"
2 x 14 12 23' - 11" 20' - 10" 19' - 5"
16 21' - 8" 18' - 0" 16' - 10"
24 17' - 9" 14' - 8" 13' - 9"

Related Topics

  • Beams and Columns

    Deflection and stress in beams and columns, moment of inertia, section modulus and technical information.

Related Documents

Search

Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

Citation

This page can be cited as

  • The Engineering ToolBox (2009). Maximum Floor Joist Span. [online] Available at: https://www.engineeringtoolbox.com/floor-joists-span-d_1479.html [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































9.26.9

.