How far can you span a 2×6, 2×8, 2×10 and 2×12 floor joist. The maximum span of floor joists depends on several factors, including the species and grade of the lumber, the spacing of the joists, and the loads they need to support. Typically, for residential construction using common softwood lumber, here are some rough guidelines for maximum spans:
1. 2×6 joists: Generally, you can span them up to 9 feet when spaced 16 inches on center.
2. 2×8 joists: You can span them up to 12 feet when spaced 16 inches on center.
3. 2×10 joists: These can span up to 15 feet when spaced 16 inches on center.
4. 2×12 joists: They can span up to 18 feet when spaced 16 inches on center.
5. 2×14 joists: They can span up to 20 feet when spaced 16 inches on center.
6. 2×16 joists: They can span up to 24 feet when spaced 16 inches on center.
The maximum span for a 2×6 floor joist depends on several factors. In general, for 2×6 joists made of Douglas fir-larch or southern pine, with a grade of No. 2 or better, you can typically span them up to 10 feet when spaced 16 inches on center for a live load of 40 pounds per square foot (psf) and a dead load of 10 psf.
The maximum span for a 2×8 floor joist depends on several factors. In general, for 2×8 joists made of Douglas fir-larch or southern pine, with a grade of No. 2 or better, you can typically span them up to 12 feet when spaced 16 inches on center.
The maximum span for a 2×10 floor joist depends on several factors. In general, for 2×10 joists made of Douglas fir-larch or southern pine, with a grade of No. 2 or better, you can typically span them up to 15 feet when spaced 16 inches on center.
The maximum span for a 2×12 floor joist depends on several factors. In general, for 2×10 joists made of Douglas fir-larch or southern pine, with a grade of No. 2 or better, you can typically span them up to 18 feet when spaced 16 inches on center.
There are different depth of floor joist are used in floor construction such as 2×6, 2×8, 2×10 and 2×12, made of different species of wood (southern yellow pine & Douglas fir) and different grade such as grade – 1, grade – 2, grade – 3. Southern yellow pine is strongest species of wood that can span more distance compared to other species of wood. Grade 1 lumber have higher strength than other grade Lumber due to fewer knots.
Floor joists can be define as several small beams. Floor joists are typically a horizontal structural member that runs across an open space of building on supporting wall or studs. Their function is similar as beams, except floor joists are supported by wall, foundations, or beams framing.
Floor joists usually run between walls or rafters to support a ceiling or floor. They transfer the dead load of the subfloor and floor finishes and live load of people, furniture and furnishings to beams, walls, headers, or foundation walls. It is like the skeleton/ framing of a building that supports the load which the floor is built to bear. Joists are technically beams that typically spans relatively short distances compared to beams and are made of wood, steel, or engineered wood or lumber.
How far can you span a 2×6, 2×8, 2×10 and 2×12 floor joist depending on different size of Lumber, species of wood, grade of wood, spacing between the joist, expected dead and live load of structure that coming to joist. The loading includes dead load of the weight of the frame structure & fixed weight and live load of People, furniture, appliances and a snow on the roof.
Not all the type of species of wood created equally strong and type of tree used to make joist affects the span allowed. Southern yellow pine is strongest species of wood that can span more distance compared to other species of wood. Grade 1 lumber have higher strength than other grade Lumber due to fewer knots.
Spacing between floor joist for different sizes are kept at 12 inches, 16 inches and 24 inches apart. The joist which are kept at lower spacing can allow longer distance to span as compared to joist spaced further apart. Standard spacing between floors joist is 16 inches.
How far can you span a 2×6, 2×8, 2×10 and 2×12 floor joist
Rule of thumb for sizing of floor joist is 24 inches on center-a foot and a quarter span per inch depth and 16 inches on center-a foot and a half span per inch depth. So a 2×8 can span 10 feet (since 8 ×1.25 = 10 ft) at 24″ on center and 16 inches on center = 8×1.5 = 12 feet span.
Rule of thumb says × 1.5 of board width. So, the maximum span for the 2×8 floor joist = 8×1.5 = 12 feet span. This only applies to 16″ on center spacing.
In general, a 2×6 floor joist can span a maximum distance of 9 feet, while a 2×8 floor joist can span a maximum distance of 12 feet. Likewise, a 2×10 floor joist can span a maximum distance of 15 feet, while a 2×12 floor joist can span a maximum distance of 18 feet. In addition, a 2×14 floor joist can span a maximum distance of 20 feet.
How far can you span a 2×6 floor joist
As per general rules and guideline, southern yellow pine, 2×6 (2-by-6) floor joists graded as #1 allows joist spans up to 12 feet 6 inches for a live load of 30 pounds per square foot when spaced 12 inches apart, 11 feet 4 inch for 16 inch spacing and 9 feet 11 inches for 24 inch spacing.
How far can you span a 2×8 floor joist
As per general rules and guideline, southern yellow pine, 2×8 (2-by-8) floor joists graded as #1 allows joist spans up to 16 feet 6 inches for a live load of 30 pounds per square foot when spaced 12 inches apart, 15 feet 0 inch for 16 inch spacing and 13 feet 1 inches for 24 inch spacing.
◆You Can Follow me on Facebook and
Subscribe our Youtube Channel
How far can you span a 2×10 floor joist
As per general rules and guideline, southern yellow pine, 2×10 (2-by-10) floor joists graded as #1 allows joist spans up to 21 feet 0 inches 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 you span a 2×12 floor joist
As per general rules and guideline, southern yellow pine, 2×12 (2-by-12) floor joists graded as #1 allows joist spans up to 25 feet 7 inches for a live load of 30 pounds per square foot when spaced 12 inches apart, 23 feet 3 inch for 16 inch spacing and 20 feet 3 inches for 24 inch spacing.
ALSO READ:-
How thick is a 2, 3 & 4 ply LVL beam
10/12 roof pitch rafter length | How long is a 10/12 pitch roof
How far can you span a 2×6, 2×8, 2×10 and 2×12 floor joist
How far can a 2×10 ceiling joist span without support
Conclusions:-
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.