Steel Deck Framing

When wood deck framing fails, the next logical material to consider is metal. Steel is a common choice.

  • The least expensive metal deck framing option
  • Stronger and more durable than wood
  • Resists warping and twisting
  • Resists decay and insects
  • Non-combustible
  • Allows for long cantilevers
  • 50-year lifespan

However, steel deck framing does have a few downsides:

  • Extremely heavy
  • Susceptible to corrosion; cannot be installed within 3000 feet of saltwater bodies
  • More expensive than wood framing

Shop Steel Deck Framing

LVL Deck Framing

Laminated Veneer Lumber (LVL) is an engineered wood product that combines the strength of multiple thin layers with the durability of pressure treatment. Think of it as a heavy-duty form of plywood.

  • The least expensive alternative framing option
  • Stronger and more durable than modern pressure treated pine
  • Resists warping and twisting
  • Resists decay and insects
  • When properly flashed with joist tape, can last up to 25 years

Composite Deck Framing

Composite deck framing, like composite decking, is made from a mixture of wood fibers and recycled plastic. It comes with all the same advantages and disadvantages as the composite decking it’s based on.

Pros:

  • Low-maintenance
  • Resists decay, insects, and warping

Cons:

  • More expensive than wood or steel
  • More flexible than wood or metal
  • Can only accomodate short cantilevers

Aluminum Deck Framing

Aluminum is a higher-end metal deck framing option. It has all the mechanical advantages of steel, but without many of steel’s drawbacks.

  • Stronger and more durable than wood
  • Resists warping and twisting
  • Resists decay and insects
  • Lightweight
  • Resists corrosion, and can be installed near saltwater
  • Non-combustible
  • Allows for long cantilevers
  • 50-year lifespan

However, aluminum is also the most expensive alternative deck framing option.

Pressure Treated Deck Framing

Pressure Treated Pine has long been the go-to for deck framing, but that’s starting to change. The quality of pressure treated products has dropped in recent years, resulting in decks that are less durable.

This degradation is caused by a variety of factors:

  • The use of different chemical treatments that are safer for people and the environment, but aren’t as good at protecting the wood
  • The use of younger trees that yield softer timber

Where once a pressure treated deck frame could be expected to last 25 years, that life expectancy has dropped to 10 years or even less! In short, pressure treated deck framing is not what it used to be. Because of this, many builders are turning to alternative framing options.

Deck Joist Size Calculator

This calculator will tell you what size (thickness x height) joists you need based on the spacing of your supporting beams (“beam spacing” or “clear span”) and the spacing of the joists themselves (“joist spacing”). It will give you the smallest joist size that will work for your specifications. You can reduce the required joist size by adding more supporting beams, thereby reducing the beam spacing and shortening the clear span, or by using a tighter joist spacing.

This is the distance from the center of one beam to the center of the next, or the distance from your house to the center of the first beam.

This is the distance between the center of one joist to the center of the next.

Deck Joist Span Charts

Pressure Treated Joist Span Charts
Deck Joist Spans without Cantileverb
Joist Speciesa Joist Size Spaced 12″ on Center Spaced 16″ on Center Spaced 24″ on Center
Southern Pine 2x6 9′11″ 9′0″ 7′7″
2x8 13′1″ 11′10″ 9′8″
2x10 16′2″ 14′0″ 11′5″
2x12 18′0″ 16′6″ 13′6″
Douglas Fir Larchd
Hem Fird
Spruce Pine Fird
2x6 9′6″ 8′8″ 7′2″
2x8 12′6″ 11′1″ 9′1″
2x10 15′8″ 13′7″ 11′1″
2x12 18′0″ 15′9″ 12′10″
Redwood
Western Cedar
Ponderosa Pinee
Red Pinee
2x6 8′10″ 8′0″ 7′0″
2x8 11′8″ 10′7″ 8′8″
2x10 14′11″ 13′0″ 10′7″
2x12 17′5″ 15′1″ 12′4″
Deck Joist Spans with Cantileverc
Joist Speciesa Joist Size Spaced 12″ on Center Spaced 16″ on Center Spaced 24″ on Center
Southern Pine 2x6 6′8″ 6′8″ 6′8″
2x8 10′1″ 10′1″ 9′8″
2x10 14′6″ 14′0″ 11′5″
2x12 18′0″ 16′6″ 13′6″
Douglas Fir Larchd
Hem Fird
Spruce Pine Fird
2x6 6′3″ 6′3″ 6′3″
2x8 9′5″ 9′5″ 9′1″
2x10 13′7″ 13′7″ 11′1″
2x12 18′0″ 15′9″ 12′10″
Redwood
Western Cedar
Ponderosa Pinee
Red Pinee
2x6 5′7″ 5′7″ 5′7″
2x8 8′6″ 8′6″ 8′6″
2x10 12′3″ 12′3″ 10′7″
2x12 16′5″ 15′1″ 12′4″
  1. No. 2 grade with wet service factor.
  2. Ground snow load, live load = 40 psf, dead load = 10 psf, L/Δ = 360.
  3. Ground snow load, live load = 40 psf, dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever with a 220-pound point load applied to end.
  4. Includes incising factor.
  5. Northern species with no incising factor
  6. Cantilevered spans not exceeding the nominal depth of the joist are permitted.
LVL Joist Span Charts

MAXIMUM JOIST SPAN—40 PSF LIVE LOAD, 10 PSF DEAD LOAD

JOIST SPECIES JOIST SIZE JOIST SPACING ON CENTER
12″ 16″ 24″
MAXIMUM DECK JOIST SPAN LENGTH (feet-inches)
PWT Treated LVL 1 – 2×6 11′1″ 10′1″ 8′11″
1 – 2×8 14′10″ 13′6″ 11′9″
1 – 2×10 18′11″ 17′2″ 15′0″
1 – 2×12 23′0″ 20′11″ 18′3″

Notes:

  1. End bearing length must be at least 1.5″.
  2. Minimum bearing cantilever is 3.5″.
  3. Maximum cantilever 2′ in addition to span shown.
  4. Design conditions outside the scope of this guide may be designed using CSD software.
  5. Joist tables are based upon 100% duration of load.
Steel Joist Span Charts

MAXIMUM JOIST SPAN—50 PSF TOTAL LOAD

JOIST TYPE JOIST THICKNESS JOIST SPACING ON CENTER
12″ 16″
MAXIMUM DECK JOIST SPAN LENGTH (feet)
New Castle Steel 1 5/8″ 15′ 13′
1 5/8″
Every Other Doubled
17′ 15′
1 5/8″
All Doubled
18′ 17′
2″ 18′ 16′
2″
Every Other Doubled
20′ 18′
2″
All Doubled
22′ 20′

MAXIMUM JOIST SPAN—75 PSF TOTAL LOAD

JOIST TYPE JOIST THICKNESS JOIST SPACING ON CENTER
12″ 16″
MAXIMUM DECK JOIST SPAN LENGTH (feet)
New Castle Steel 1 5/8″ 14′ 12′
1 5/8″
Every Other Doubled
16′ 14′
1 5/8″
All Doubled
18′ 16′
2″ 18′ 16′
2″
Every Other Doubled
20′ 18′
2″
All Doubled
22′ 20′

MAXIMUM JOIST SPAN—100 PSF TOTAL LOAD

JOIST TYPE JOIST THICKNESS JOIST SPACING ON CENTER
12″ 16″
MAXIMUM DECK JOIST SPAN LENGTH (feet)
New Castle Steel 1 5/8″ 12′ 11′
1 5/8″
Every Other Doubled
14′ 12′
1 5/8″
All Doubled
16′ 14′
2″ 16′ 15′
2″
Every Other Doubled
19′ 17′
2″
All Doubled
21′ 19′

MAXIMUM JOIST SPAN—125 PSF TOTAL LOAD

JOIST TYPE JOIST THICKNESS JOIST SPACING ON CENTER
12″ 16″
MAXIMUM DECK JOIST SPAN LENGTH (feet)
New Castle Steel 1 5/8″ 10′ 9′
1 5/8″
Every Other Doubled
12′ 10′
1 5/8″
All Doubled
14′ 12′
2″ 15′ 14′
2″
Every Other Doubled
17′ 16′
2″
All Doubled
19′ 17′

MAXIMUM JOIST SPAN—150 PSF TOTAL LOAD

JOIST TYPE JOIST THICKNESS JOIST SPACING ON CENTER
12″ 16″
MAXIMUM DECK JOIST SPAN LENGTH (feet)
New Castle Steel 1 5/8″ 9′ 8′
1 5/8″
Every Other Doubled
10′ 9′
1 5/8″
All Doubled
12′ 10′
2″ 14′ 13′
2″
Every Other Doubled
16′ 14′
2″
All Doubled
18′ 16′

MAXIMUM JOIST SPAN—200 PSF TOTAL LOAD

JOIST TYPE JOIST THICKNESS JOIST SPACING ON CENTER
12″ 16″
MAXIMUM DECK JOIST SPAN LENGTH (feet)
New Castle Steel 1 5/8″ 8′ 7′
1 5/8″
Every Other Doubled
9′ 7′
1 5/8″
All Doubled
10′ 8′
2″ 13′ 11′
2″
Every Other Doubled
15′ 13′
2″
All Doubled
16′ 15′

Deck Beam Span Charts

Pressure Treated Beam Span Charts

Data collected from IRC 2021, Part 3, Chapter 5, Section R507.5.

TABLE R507.5(1)

MAXIMUM DECK BEAM SPAN—40 PSF LIVE LOADc

BEAM SPECIESd BEAM SIZEe EFFECTIVE DECK JOIST SPAN LENGTHa, i, j (feet)
6′ 8′ 10′ 12′ 14′ 16′ 18′
MAXIMUM DECK BEAM SPAN LENGTH (feet-inches)a, b, f
Southern pine 1 – 2×6 4′7″ 4′0″ 3′7″ 3′3″ 3′0″ 2′10″ 2′8″
1 – 2×8 5′11″ 5′1″ 4′7″ 4′2″ 3′10″ 3′7″ 3′5″
1 – 2×10 7′0″ 6′0″ 5′5″ 4′11″ 4′7″ 4′3″ 4′0″
1 – 2×12 8′3″ 7′1″ 6′4″ 5′10″ 5′5″ 5′0″ 4′9″
2 – 2×6 6′11″ 5′11″ 5′4″ 4′10″ 4′6″ 4′3″ 4′0″
2 – 2×8 8′9″ 7′7″ 6′9″ 6′2″ 5′9″ 5′4″ 5′0″
2 – 2×10 10′4″ 9′0″ 8′0″ 7′4″ 6′9″ 6′4″ 6′0″
2 – 2×12 12′2″ 10′7″ 9′5″ 8′7″ 8′0″ 7′5″ 7′0″
3 – 2×6 8′6″ 7′5″ 6′8″ 6′1″ 5′8″ 5′3″ 4′11″
3 – 2×8 10′11″ 9′6″ 8′6″ 7′9″ 7′2″ 6′8″ 6′4″
3 – 2×10 13′0″ 11′2″ 10′0″ 9′2″ 8′6″ 7′11″ 7′6″
3 – 2×12 15′3″ 13′3″ 11′10″ 10′9″ 10′0″ 9′4″ 8′10″
Douglas fir-larchg

Hem-firg

Spruce-pine-fir
1 – 2 x 6 4′1″ 3′6″ 3′0″ 2′8″ 2′5″ 2′3″ 2′1″
1 – 2×8 5′6″ 4′8″ 4′0″ 3′6″ 3′2″ 2′11″ 2′9″
1 – 2×10 6′8″ 5′10″ 5′1″ 4′6″ 4′1″ 3′9″ 3′6″
1 – 2×12 7′9″ 6′9″ 6′0″ 5′6″ 5′0″ 3′9″ 3′6″
2 – 2×6 6′1″ 5′3″ 4′9″ 4′4″ 3′11″ 3′7″ 3′3″
2 – 2×8 8′2″ 7′1″ 6′4″ 5′9″ 5′2″ 4′8″ 4′4″
2 – 2×10 10′0″ 8′7″ 7′9″ 7′0″ 6′6″ 6′0″ 5′6″
2 – 2×12 11′7″ 10′0″ 8′11″ 8′2″ 7′7″ 7′1″ 6′8″
3 – 2×6 7′8″ 6′8″ 6′0″ 5′6″ 5′1″ 4′9″ 4′6″
3 – 2×8 10′3″ 8′10″ 7′11″ 7′3″ 6′8″ 6′3″ 5′11″
3 – 2×10 12′6″ 10′10″ 9′8″ 8′10″ 8′2″ 7′8″ 7′2″
3 – 2×12 14′6″ 12′7″ 11′3″ 10′3″ 9′6″ 8′11″ 8′5″
Redwoodh

Western cedarsh

Ponderosa pineh

Red pineh
1 – 2×6 4′2″ 3′7″ 3′1″ 2′9″ 2′6″ 2′3″ 2′2″
1 – 2×8 5′4″ 4′7″ 4′1″ 3′7″ 3′3″ 3′0″ 2′10″
1 – 2×10 6′6″ 5′7″ 5′0″ 4′7″ 4′2″ 3′10″ 3′7″
1 – 2×12 7′6″ 6′6″ 5′10″ 5′4″ 4′11″ 4′7″ 4′4″
2 – 2×6 6′2″ 5′4″ 4′10″ 4′5″ 4′0″ 3′8″ 3′4″
2 – 2×8 7′10″ 6′10″ 6′1″ 5′7″ 5′2″ 4′10″ 4′5″
2 – 2×10 9′7″ 8′4″ 7′5″ 6′9″ 6′3″ 5′10″ 5′6″
2 – 2×12 11′1″ 9′8″ 8′7″ 7′10″ 7′3″ 6′10″ 6′5″
3 – 2×6 7′8″ 6′9″ 6′0″ 5′6″ 5′1″ 4′9″ 4′6″
3 – 2×8 9′10″ 8′6″ 7′7″ 6′11″ 6′5″ 6′0″ 5′8″
3 – 2×10 12′0″ 10′5″ 9′4″ 8′6″ 7′10″ 7′4″ 6′11″
3 – 2×12 13′11″ 12′1″ 10′9″ 9′10″ 9′1″ 8′6″ 8′1″

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.

  1. Interpolation permitted. Extrapolation not permitted.

  2. Beams supporting a single span of joists with or without cantilever.

  3. Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load is not assumed to be concurrent with live load.

  4. No. 2 grade, wet service factor included.

  5. Beam depth shall be equal to or greater than the depth of intersecting joist for a flush beam connection.

  6. Beam cantilevers are limited to the adjacent beam’s span divided by 4.

  7. Includes incising factor.

  8. Incising factor not included.

  9. Deck joist span as shown in Figure R507.5.

  10. For calculation of effective deck joist span, the actual joist span length shall be multiplied by the joist span factor in accordance with Table R507.5(5).

TABLE R507.5(2)

MAXIMUM DECK BEAM SPAN—50 PSF GROUND SNOW LOADc

BEAM SPECIESd BEAM SIZEe EFFECTIVE DECK JOIST SPAN LENGTH (feet)a, i, j
6′ 8′ 10′ 12′ 14′ 16′ 18′
MAXIMUM DECK BEAM SPAN LENGTH (feet-inches)a, b, f
Southern pine 1 – 2×6 4′6″ 3′11″ 3′6″ 3′2″ 2′11″ 2′9″ 2′7″
1 – 2×8 5′9″ 4′11″ 4′5″ 4′0″ 3′9″ 3′6″ 3′3″
1 – 2×10 6′9″ 5′10″ 5′3″ 4′9″ 4′5″ 4′2″ 3′11″
1 – 2×12 8′0″ 6′11″ 6′2″ 5′8″ 5′3″ 4′11″ 4′7″
2 – 2×6 6′8″ 5′9″ 5′2″ 4′9″ 4′4″ 4′1″ 3′10″
2 – 2×8 8′6″ 7′4″ 6′7″ 6′0″ 5′7″ 5′2″ 4′11″
2 – 2×10 10′1″ 8′9″ 7′10″ 7′1″ 6′7″ 6′2″ 5′10″
2 – 2×12 11′11″ 10′3″ 9′2″ 8′5″ 7′9″ 7′3″ 6′10″
3 – 2×6 7′11″ 7′2″ 6′6″ 5′11″ 5′6″ 5′1″ 4′10″
3 – 2×8 10′5″ 9′3″ 8′3″ 7′6″ 6′11″ 6′6″ 6′2″
3 – 2×10 12′8″ 10′11″ 9′9″ 8′11″ 8′3″ 7′9″ 7′3″
3 – 2×12 14′11″ 12′11″ 11′6″ 10′6″ 9′9″ 9′1″ 8′7″
Douglas fir-larchg

Hem-firg

Spruce-pine-firg
1 – 2×6 4′0″ 3′5″ 2′11″ 2′7″ 2′4″ 2′2″ 2′0″
1 – 2×8 5′4″ 4′7″ 3′11″ 3′5″ 3′1″ 2′10″ 2′8″
1 – 2×10 6′7″ 5′8″ 4′11″ 4′5″ 4′0″ 3′8″ 3′5″
1 – 2×12 7′7″ 6′7″ 5′11″ 5′4″ 4′10″ 4′6″ 4′2″
2 – 2×6 6′0″ 5′2″ 4′7″ 4′2″ 3′10″ 3′5″ 3′2″
2 – 2×8 8′0″ 6′11″ 6′2″ 5′8″ 5′0″ 4′7″ 4′2″
2 – 2×10 9′9″ 8′5″ 7′7″ 6′11″ 6′4″ 5′10″ 5′4″
2 – 2×12 11′4″ 9′10″ 8′9″ 8′0″ 7′5″ 6′11″ 6′6″
3 – 2×6 7′6″ 6′6″ 5′9″ 5′3″ 4′11″ 4′7″ 4′4″
3 – 2×8 10′0″ 8′8″ 7′9″ 7′1″ 6′6″ 6′1″ 5′8″
3 – 2×10 12′3″ 10′7″ 9′6″ 8′8″ 8′0″ 7′6″ 7′0″
3 – 2×12 14′3″ 12′4″ 11′0″ 10′1″ 9′4″ 8′9″ 8′3″
Redwoodh

Western cedarsh

Ponderosa pineh

Red pineh
1 – 2×6 4′1″ 3′6″ 3′0″ 2′8″ 2′5″ 2′3″ 2′1″
1 – 2×8 5′2″ 4′6″ 4′0″ 3′6″ 3′2″ 2′11″ 2′9″
1 – 2×10 6′4″ 5′6″ 4′11″ 4′6″ 4′1″ 3′9″ 3′6″
1 – 2×12 7′4″ 6′4″ 5′8″ 5′2″ 4′10″ 4′6″ 4′3″
2 – 2×6 6′1″ 5′3″ 4′8″ 4′4″ 3′11″ 3′6″ 3′3″
2 – 2×8 7′8″ 6′8″ 5′11″ 5′5″ 5′0″ 4′8″ 4′3″
2 – 2×10 9′5″ 8′2″ 7′3″ 6′8″ 6′2″ 5′9″ 5′5″
2 – 2×12 10′11″ 9′5″ 8′5″ 7′8″ 7′2″ 6′8″ 6′3″
3 – 2×6 7′1″ 6′5″ 5′11″ 5′5″ 5′0″ 4′8″ 4′5″
3 – 2×8 9′4″ 8′4″ 7′5″ 6′10″ 604 5′11″ 5′7″
3 – 2×10 11′9″ 10′2″ 9′1″ 8′4″ 7′8″ 7′2″ 6′9″
3 – 2×12 13′8″ 11′10″ 10′7″ 9′8″ 8′11″ 8′4″ 7′10″

For SI: 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.

  1. Interpolation allowed. Extrapolation is not allowed.

  2. Beams supporting a single span of joists with or without cantilever.

  3. Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.

  4. No. 2 grade, wet service factor included.

  5. Beam depth shall be equal to or greater than the depth of intersecting joist for a flush beam connection.

  6. Beam cantilevers are limited to the adjacent beam’s span divided by 4.

  7. Includes incising factor.

  8. Incising factor not included.

  9. Deck joist span as shown in Figure R507.5.

  10. For calculation of effective deck joist span, the actual joist span length shall be multiplied by the joist span factor in accordance with Table R507.5(5).

TABLE R507.5(3)

MAXIMUM DECK BEAM SPAN—60 PSF GROUND SNOW LOADc

BEAM SPECIESd BEAM SIZEe EFFECTIVE DECK JOIST SPAN LENGTHa, i, j (feet)
6′ 8′ 10′ 12′ 14′ 16′ 18′
MAXIMUM DECK BEAM SPAN LENGTH (feet-inches)a, b, f
Southern pine 1 – 2×6 4′2″ 3′7″ 3′3″ 2′11″ 2′9″ 2′6″ 2′5″
1 – 2×8 5′3″ 4′7″ 4′1″ 3′9″ 3′5″ 3′3″ 3′0″
1 – 2×10 6′3″ 5′5″ 4′10″ 4′5″ 4′1″ 3′10″ 3′7″
1 – 2×12 7′5″ 6′5″ 5′9″ 5′3″ 4′10″ 4′6″ 4′3″
2 – 2×6 6′2″ 5′4″ 4′9″ 4′4″ 4′0″ 3′9″ 3′7″
2 – 2×8 7′10″ 6′10″ 6′1″ 5′7″ 5′2″ 4′10″ 4′6″
2 – 2×10 9′4″ 8′1″ 7′3″ 6′7″ 6′1″ 5′8″ 5′4″
2 – 2×12 11′0″ 9′6″ 8′6″ 7′9″ 7′2″ 6′9″ 6′4″
3 – 2×6 7′5″ 6′9″ 6′0″ 5′6″ 5′1″ 4′9″ 4′6″
3 – 2×8 9′9″ 8′6″ 7′8″ 6′11″ 6′5″ 6′0″ 5′8″
3 – 2×10 11′8″ 10′2″ 9′1″ 8′3″ 7′8″ 7′2″ 6′9″
3 – 2×12 13′9″ 11′11″ 10′8″ 9′9″ 9′0″ 8′5″ 7′11″
Douglas fir-larchg

Hem-firg

Spuce-pine-firg
1 – 2×6 3′8″ 3′1″ 2′8″ 2′4″ 2′2″ 2′0″ 1′10″
1 – 2×8 5′0″ 4′1″ 3′6″ 3′1″ 2′10″ 2′7″ 2′5″
1 – 2×10 6′1″ 5′2″ 4′6″ 4′0″ 3′7″ 3′4″ 3′2″
1 – 2×12 7′1″ 6′1″ 5′5″ 4′10″ 4′5″ 4′1″ 3′10″
2 – 2×6 5′6″ 4′9″ 4′3″ 3′10″ 3′5″ 3′1″ 2′10″
2 – 2×8 7′5″ 6′5″ 5′9″ 5′0″ 4′6″ 4′1″ 3′9″
2 – 2×10 9′0″ 7′10″ 7′0″ 6′4″ 5′9″ 5′2″ 4′10″
2 – 2×12 10′6″ 9′1″ 8′1″ 7′5″ 6′10″ 6′4″ 5′10″
3 – 2×6 6′11″ 6′0″ 5′4″ 4′11″ 4′6″ 4′2″ 3′10″
3 – 2×8 9′3″ 8′0″ 7′2″ 6′6″ 6′1″ 5′6″ 5′0″
3 – 2×10 11′4″ 9′10″ 8′9″ 8′0″ 7′5″ 6′11″ 6′5″
3 – 2×12 13′2″ 11′5″ 10′2″ 9′4″ 8′7″ 8′1″ 7′7″
Redwoodh

Western cedarsh

Ponderosa pineh

Red pineh
1 – 2×6 3′9″ 3′2″ 2′9″ 2′5″ 2′2″ 2′0″ 1′11″
1 – 2×8 4′10″ 4′2″ 3′7″ 3′2″ 2′11″ 2′8″ 2′6″
1 – 2×10 5′10″ 5′1″ 4′6″ 4′1″ 3′8″ 3′5″ 3′3″
1 – 2×12 6′10″ 5′11″ 5′3″ 4′10″ 4′5″ 4′2″ 3′11″
2 – 2×6 5′7″ 4′10″ 4′4″ 3′11″ 3′6″ 3′2″ 2′11″
2 – 2×8 7′1″ 6′2″ 5′6″ 5′0″ 4′7″ 4′2″ 3′10″
2 – 2×10 8′8″ 7′6″ 6′9″ 6′2″ 5′8″ 5′4″ 4′11″
2 – 2×12 10′1″ 8′9″ 7′10″ 7′2″ 6′7″ 6′2″ 5′10″
3 – 2×6 6′8″ 6′1″ 5′5″ 5′0″ 4′7″ 4′3″ 3′11″
3 – 2×8 8′9″ 7′9″ 6′22″ 6′4″ 5′20″ 5′5″ 5′3″
3 – 2×10 10′11″ 9′5″ 8′5″ 7′8″ 7′3″ 6′8″ 6′3″
3 – 2×12 12′8″ 10′11″ 9′9″ 8′11″ 8′3″ 7′9″ 7′3″

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.

  1. Interpolation allowed. Extrapolation is not allowed.

  2. Beams supporting a single span of joists with or without cantilever.

  3. Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.

  4. No. 2 grade, wet service factor included.

  5. Beam depth shall be equal to or greater than the depth of intersecting joist for a flush beam connection.

  6. Beam cantilevers are limited to the adjacent beam’s span divided by 4.

  7. Includes incising factor.

  8. Incising factor not included.

  9. Deck joist span as shown in Figure R507.5.

  10. For calculation of effective deck joist span, the actual joist span length shall be multiplied by the joist span factor in accordance with Table R507.5(5).

TABLE R507.5(4)

MAXIMUM DECK BEAM SPAN—70 PSF GROUND SNOW LOADc

BEAM SPECIESd BEAM SIZEe EFFECTIVE DECK JOIST SPAN LENGTH (feet)a, i, j
6′ 8′ 10′ 12′ 14′ 16′ 18′
MAXIMUM DECK BEAM SPAN LENGTH (feet-inches)a, b, f
Southern pine 1 – 2×6 3′11″ 3′4″ 3′0″ 2′9″ 2′6″ 2′4″ 2′3″
1 – 2×8 4′11″ 4′3″ 3′10″ 3′6″ 3′3″ 3′0″ 2′10″
1 – 2×10 5′10″ 5′1″ 4′6″ 4′2″ 3′10″ 3′7″ 3′4″
1 – 2×12 6′11″ 6′0″ 5′4″ 4′11″ 4′6″ 4′3″ 4′0″
2 – 2×6 5′9″ 5′0″ 4′6″ 4′1″ 3′9″ 3′6″ 3′4″
2 – 2×8 7′4″ 6′4″ 5′8″ 5′2″ 4′10″ 4′6″ 4′3″
2 – 2×10 8′9″ 7′7″ 6′9″ 6′2″ 5′8″ 5′4″ 5′0″
2 – 2×12 10′3″ 8′11″ 8′0″ 7′3″ 6′9″ 6′3″ 5′11″
3 – 2×6 7′0″ 6′3″ 5′7″ 5′1″ 4′9″ 4′5″ 4′2″
3 – 2×8 9′3″ 8′0″ 7′2″ 6′6″ 6′0″ 5′8″ 5′4″
3 – 2×10 10′11″ 9′6″ 8′6″ 7′9″ 7′2″ 6′8″ 6′4″
3 – 2×12 12′11″ 11′2″ 10′0″ 9′1″ 8′5″ 7′11″ 7′5″
Douglas fir-larchg

Hem-firg

Spruce-pine-firg
1 – 2×6 3′5″ 2′10″ 2′5″ 2′2″ 2′0″ 1′10″ 1′9″
1 – 2×8 4′7″ 3′8″ 3′2″ 2′10″ 2′7″ 2′5″ 2′4″
1 – 2×10 5′8″ 4′9″ 4′1″ 3′8″ 3′4″ 3′1″ 2′11″
1 – 2×12 6′7″ 5′8″ 5′0″ 4′6″ 4′1″ 3′10″ 3′7″
2 – 2×6 5′2″ 4′6″ 4′0″ 3′5″ 3′1″ 2′10″ 2′7″
2 – 2×8 6′11″ 6′0″ 5′3″ 4′7″ 4′1″ 3′8″ 3′5″
2 – 2×10 8′5″ 7′4″ 6′6″ 5′10″ 5′2″ 4′9″ 4′5″
2 – 2×12 9′10″ 8′6″ 7′7″ 6′11″ 6′4″ 5′9″ 5′4″
3 – 2×6 6′6″ 5′7″ 5′0″ 4′7″ 4′2″ 3′9″ 3′5″
3 – 2×8 8′8″ 7′6″ 6′8″ 6′1″ 5′6″ 5′0″ 4′7″
3 – 2×10 10′7″ 9′2″ 8′2″ 7′6″ 6′11″ 6′4″ 5′10″
3 – 2×12 12′4″ 10′8″ 9′7″ 8′9″ 8′1″ 7′7″ 7′1″
Redwoodh

Western cedarsh

Ponderosa pineh

Red pineh
1 – 2×6 3′6″ 2′11″ 2′6″ 2′3″ 2′0″ 1′11″ 1′9″
1 – 2×8 4′6″ 3′10″ 3′3″ 2′11″ 2′8″ 2′6″ 2′4″
1 – 2×10 5′6″ 4′9″ 4′2″ 3′9″ 3′5″ 3′2″ 3′0″
1 – 2×12 6′4″ 5′6″ 4′11″ 4′6″ 4′2″ 3′11″ 3′8″
2 – 2×6 5′3″ 4′7″ 4′1″ 3′6″ 3′2″ 2′11″ 2′8″
2 – 2×8 6′8″ 5′9″ 5′2″ 4′8″ 4′2″ 3′10″ 3′6″
2 – 2×10 8′2″ 7′1″ 6′4″ 5′9″ 5′4″ 4′10″ 4′6″
2 – 2×12 9′5″ 8′2″ 7′4″ 6′8″ 6′2″ 5′9″ 5′5″
3 – 2×6 6′4″ 5′8″ 5′1″ 4′8″ 4′3″ 3′10″ 3′6″
3 – 2×8 8′4″ 7′3″ 6′5″ 5′11″ 5′5″ 5′1″ 4′8″
3 – 2×10 10′2″ 8′10″ 7′11″ 7′2″ 6′8″ 6′3″ 5′11″
3 – 2×12 11′10″ 10′3″ 9′2″ 8′4″ 7′9″ 7′3″ 6′10″

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square foot = 0.0479 kPa, 1 pound = 0.454 kg.

  1. Interpolation allowed. Extrapolation is not allowed.

  2. Beams supporting a single span of joists with or without cantilever.

  3. Dead load = 10 psf, L/Δ = 360 at main span, L/Δ = 180 at cantilever. Snow load not assumed to be concurrent with live load.

  4. No. 2 grade, wet service factor included.

  5. Beam depth shall be equal to or greater than the depth of intersecting joist for a flush beam connection.

  6. Beam cantilevers are limited to the adjacent beam’s span divided by 4.

  7. Includes incising factor.

  8. Incising factor not included.

  9. Deck joist span as shown in Figure R507.5.

  10. For calculation of effective deck joist span, the actual joist span length shall be multiplied by the joist span factor in accordance with Table R507.5(5).

TABLE R507.5(5)

JOIST SPAN FACTORS FOR CALCULATING EFFECTIVE DECK JOIST SPAN [for use with Note j in Tables R507.5(1), R507.5(2), R507.5(3) and R507.5(4)]

C/Ja JOIST SPAN FACTOR
0 (no cantilever) 0.66
1/12 (0.87) 0.72
1/10 (0.10) 0.80
1/8 (0.125) 0.84
1/6 (0.167) 0.90
1/4 (0.250) 1.00

For SI: 1 foot = 304.8 mm.

  1. C = actual joist cantilever length (feet); J = actual joist span length (feet).

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