A 2×12 (2-by-12) floor joists can span up to 23 feet 3 inches, 2×10 (2-by-10) up to 19 feet 1 inches, 2×8 (2-by-8) up to 15 feet & 2×6 (2-by-6) up to 11 feet 4 inches at 16″ spaced by using southern yellow pine graded as #1 when live load of 30 lbs/ft^2 & dead load of 10 lbs/ ft^2.
Full Answer
How to calculate floor joist?
Joist Span Calculator
- Select a load. There are six choices. The lowest is a plain ceiling joist with no storage (10 pounds per square foot). ...
- Select the on center spacing for the joists. This is how far apart they will be. ...
- Enter a span for the joist. This will be slightly less than the length of the board. ...
- Finally, select a type of lumber. No. ...
What size floor joist for 12 ft span?
- Depth of structural members. Often, 2×10 joists spaced 24-inches o.c. ...
- E value or modulus of elasticity of the individual elements. E is a ratio that relates the amount a given load causes a material to deform. ...
- Fb value or extreme fiber stress in bending. Loads cause beams, joists and rafters to bend. ...
- Lumber grade. ...
- Species of wood. ...
- Duration of load. ...
How big is 2x12 lumber?
The standard size for framing lumber that has a nominal size of "2 x 12" is 1.5" x 11.25", same as a "2x4" is actually 1.5" x 3.5", etc.
What is the best wood for floor joists?
- southern yellow pine.
- Red oak.
- Douglus fir.
- White ceder.
- Pine – white.
- Spruce sitka.
- Hard maple.
How far can you span a 2X12 floor joist?
A 2×12 (2-by-12) floor joists can span up to 23 feet 3 inches, 2×10 (2-by-10) up to 19 feet 1 inches, 2×8 (2-by-8) up to 15 feet & 2×6 (2-by-6) up to 11 feet 4 inches at 16″ spaced by using southern yellow pine graded as #1 when live load of 30 lbs/ft^2 & dead load of 10 lbs/ ft^2.
How many feet can a 2X12 span?
Max. Live Load 30 lbs/ft2 (1436 N/m2)Maximum Span (ft - in)Nominal Size (inches)Joist Spacing Center to Center (inches)Lumber Grade2 x 121223' - 0"1619' - 11"2416' - 3"10 more rows
Can a 2X12 span 20 feet?
In general terms, joist or beam which spaced 16 inches apart on Centre can span 1.5 times in feet their depth in inches. A 2×14 can span upto 20 feet. What size beam to span 20 ft:- as per general thumb rule and guidelines, a 4 nailed 2×16 or 4-2×16 or 8×16 size of wood beam can allow to span 20 ft.
What size floor joist do I need for a 16 foot span?
What size floor joist to span 16 feet:- as per general rules and guideline, a 2×8 (2-by-8) size of floor joists made of southern yellow pine, graded as #1 can allows joist spans up to 16 feet for a live load of 30 pounds per square foot and dead load of 10 pounds per square foot when spaced 16 inches apart.
How far can a double 2x12 span without support?
A double 2x12 beam can span 12 feet; a (2) 2x10 can span 10 feet and so on.
How much load can a 2x12 support?
One 2x12 can support about 180 lbs. per foot or about 2,100 lbs. total for a 12' span.
What size beam do I need for an 18 foot span?
Thus, for a 18 foot span, you will need atleast 3-2×16 or 6×16 size of wood beam. For a 18-foot spans, the wood beam has to be at least 16 inches in depth and 6″ in width (3-2×16) used for residential building, wood frame structure or projects.
What size beam do I need to 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.
How big of a beam do I need to span 16 feet?
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.
Can floor joists span 16 feet?
Floor joist span is the length of an individual joist, from the foundation walls to an interior beam. The spacing between joists is typically 16”, but can also be 12”, 20”, and 24”. The spacing and ability to span a greater – or smaller – distance is dependent on the size of lumber used for the joists.
Can a 2x10 span 16 feet?
Douglas fir 2-by-10 joists graded as "Structural Select" allows joist spans up to 21 feet for a live load of 30 pounds per square foot when spaced 12 inches apart, 19 feet 1 inch for 16 inch spacing and 16 feet 8 inches for 24 inch spacing.
How far can a 2 by 8 floor joist span?
Span is determined by species, grade, dimensions, spacing, use, and load. A rule of thumb is 1.5 times a joist's depth but in feet when spaced at 16” centers. In general, a 2×8 will span 1.5 x 8, so 12-feet. Based on all factors though, a 2×8 joist span is 7'-1” to 16'-6”, and a rafter 6'-7” and 23'-9”.
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Which Way do Floor Joists Run?
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How Much Weight Can Floor Joists Support?
As discussed earlier in this post, a floor joist can generally hold between 30 and 40 pounds per square foot (PSF). Floor joists are designed to su...
Can You Notch a Floor Joist?
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Are Floor Joists Treated?
In most cases, floor joists are made from untreated lumber. However, there are a few exceptions. If your home is in a moist or humid environment, y...
How long can a 2x6 joist span?
For example, a 2×6 Southern Pine joist can span 12’. A 2×12 joist of the same species and quality can span nearly 25’. The spans listed in the span tables of the IRC indicate max span, so many contractors will often overbuild a floor for the sake of stability. So, if there is a span of 11’, 2x8s are often used even though 2x6s are technically acceptable.
How Far Can Floor Joists Span?
A floor joist can span nearly 26’ in the most extreme cases. A select douglas fir 2×12 supporting a 30 psf live load and 10 psf dead load, spaced at 12” will have the greatest span length. However, you would only be able to use this beneath a sleeping area since it is rated for 30 psf, not 40.
What type of lumber is used for floor joists?
Other species, such as spruce, pine, and/or fir are also quite common. Douglas fir , hemlock, and larch round out the species found on the floor joist span tables.
Why are there no I beam floor joist span tables?
That is why there are no I-beam floor joist span tables in the IRC – because they couldn’t possibly account for all the different types of I-beams on the market.
What is the correct floor joist size?
It outlines max span lengths for wood joists of all sizes – from 2×6 to 2×12 and greater. The code also identifies joist sizing and spans for various joist spacing – from 12” up to 24” apart.
How much load is in a span table?
When you look at the IRC, you’ll notice two separate span tables for floor joists. One is for 30 pounds per square foot (psf) of live load, and the other is for 40 psf.
Why is there no standard floor joist span?
There is no standard floor joist span length simply because every home is unique. It just takes one look at a floor joist span table to tell you that there are many combinations of variables when it comes to floor joists.
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Joists & Rafters
Simplified maximum span tables for selected visual and mechanical grades of Southern Pine lumber in sizes 2×4 thru 2×12. Listed are 46 tables based on common loading conditions for floor joists, ceiling joists and rafters.
Headers & Beams
Simplified span tables for Southern Pine lumber and glued laminated timber (glulam) headers, beams and girders.
How far can a 2x8 span?
In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2x8 up to 12 feet; 2x10 to 15 feet and 2x12 to 18 feet.
How much weight can a 2x12 support?
One 2x12 can support about 180 lbs. per foot or about 2,100 lbs.
How far can a double ply beam span?
When supporting joists that span 12 feet with no overhang beyond the beam, a double ply beam can span in feet a value equal to its depth in inches. A double 2x12 beam can span 12 feet; a (2) 2x10 can span 10 feet and so on. Click to see full answer.
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.
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Citation
Engineering ToolBox, (2009). Maximum Floor Joist Span. [online] Available at: https://www.engineeringtoolbox.com/floor-joists-span-d_1479.html [Accessed Day Mo. Year].