How do I know what size beam I need?

Calculate the maximum bending moment for the wooden beams. The bending moment is the length of the span times the weight to be supported divided by 8. For a beam spanning a 12-foot room and supporting a weight of 600 lbs., the maximum bending moment would be 12 x 600/8 = 900 foot-pounds.

What size beam do I need for a 20 foot span?





For a 20-foot spans, the wood beam has to be at least 16 inches in depth and 8″ in width (4-2×16) used for residential building or projects.

What size beam do I need for a 12 foot span?

A double 2×12 beam can span 12 feet; a (2) 2×10 can span 10 feet and so on.

What size beam do I need for a 10 foot span?

A double ply beam can span in feet if there is no overhang beyond it. A double 2×12 beam can span 12 feet, a double 2×10 can span 10 feet, and so on.

What size beam do I need for an 18 foot span?

Wood beam size for a 18 foot span:– as per general thumb rule, for a 18 foot span, size of wood beam or lumber joist should be 2×12 which placed at 16″ apart from centre used for residential building or projects or construction in which depth of section of beam is 300mm (12″) and width of beam is 50 mm or 2″.

How big of a beam do I need to span 18 feet?





For span upto 18 feet, generally you need 3 × 9 1/4 standard size of LVL beam or 2×12 dimensional lumber at 16″ apart from centre on normal weight condition which providing great stability for your projects.

What size lumber can span 24 feet?

What size beam to span 24 ft:- as per general thumb rule and guidelines, a 4 nailed 2×18 or 4-2×18 or 8×18 size of wood beam can allow to span 24 feet. Thus, for a 24 foot span, you will need atleast 4-2×18 or 8×18 size of wood beam.

What size beam do I need to span 15 feet?

Thus, for a 15 foot span, you will need atleast 3-2×12 or 6×12 size of wood beam. For a 15-foot spans, the wood beam has to be at least 12 inches in depth and 6″ in width (3-2×12) used for residential building, wood frame structure or projects.

What size beam do I need for a 16 foot span?

For a 16 foot span, you will need atleast 3-2×14 or 6×14 size of wood beam. Thus, a 3 nailed 2×14 or 3-2×14 or 6×14 wood beam can allow to span 16 feet. For a 16-foot spans, the wood beam has to be at least 14 inches in depth and 6″ in width (3-2×14) used for residential building, wood frame structure or projects.

What size beam do I need to span 13 feet?



Wood beam size for a 13 foot span:- as per general thumb rule, for a 13 foot span, size of wood beam or lumber joist should be 2×10 which placed at 16″ apart from centre used for residential building or projects or construction in which depth of section of beam is 250mm (10″) and width of beam is 50 mm or 2″.

What size lumber can span 10 feet?

2-grade 2×6 joists can span up to 10 feet 9 inches from beam to beam when spaced the standard 16 inches apart with a maximum live load of 30 inches per square foot.

Can a 6X6 span 10 feet?

To answer you question, no a 6X6 will not carry that span, even if you have only a roof to support. The strength is in the height of the beam, not so much for the width.

What is the maximum span for a 4X12 beam?



Dimensional Lumber Deck Beam Span Chart

Joist Spans
Douglas Fir-Larch, Hem-Fir, Spruce-Pine-Fir, Redwood, Cedars, Ponderosa Pine, Red Pine 4X10 8′-4″
4X12 9′-8″
3-2X6 6′-5″
3-2X8 8′-3″

How much weight will a 6×6 hold?

A 6×6 with 12′ span can support 2000 lbs. if you assume a conservative 1400psi bending stress. If you do a good job bonding the two members together, your double 6×6 can support more than 4,000 lbs.

Are two 2X6 stronger than a 4×6?

A 4X6 in many cases is a large chunk of today’s trees. With younger trees the 2 ea 2×6’s are much stronger than a 4×6. I work in a small lumber mill and would never use a 4×6 on a long span because the knots are all in the same location so there is less strength there also.

What is stronger 4×6 or 2×8?

Unless it comes a ways from the pith of the log it will be stronger if it comes from a “boxed heart” timber. A good 2×8 will support as much as a 4×6.

How far can a doubled up 2×6 span?



Double 2×6 Beam Span

For joist spans of 8′ or less, the beam span is 5’11” and 4′-8” respectively, and 5′-4” and 4′-2” if the span is 10′ or less. A double 2×6 header can span between 2′-1” and 6′-0” for exterior walls depending on building width, snow load, number of floors, and location and number of bearing walls.

Which is stronger 2 2×4 or 1 2×6?

So if a double 2×4 has bending strength of (3″)*(3.5″)^3 = 128.6, then a single 2×6 has (1.5″)*(5.5″)^3 = 249.6. This means a single 2×6 is almost twice as strong in bending as a double 2×4.

Which is stronger a 4×4 or 2 2×4?

When used vertically, 4x4s are stronger than two 2x4s. However, if you need a horizontal surface, two 2x4s will be stronger than one 4×4. A 4×4 should not be used horizontally for anything structural. Always be sure that you’re using the proper size and strength of lumber.

Can I use 2×4 for floor joists?



A 2×4 can span a maximum of 6′ 7” when spaced 16” apart and used as a floor or deck joist. When used as a ceiling joist or a roof rafter, a 2×4 can span up to 7′ 3” spaced at 16”, and 6′ 4” when spaced 24” apart. Due to the small spans of 2x4s, they often are not used in horizontal load-bearing capacities.