Built-up beams (multiple 2x boards nailed together) carry loads across openings. These are rough maximum spans for a beam supporting one floor level — the real span depends heavily on the load width it carries.
| Built-up beam | Approx. max span |
|---|---|
| (2) 2×8 | about 6 ft |
| (2) 2×10 | about 7 ft |
| (2) 2×12 | about 8 ft |
| (3) 2×10 | about 9 ft |
| (3) 2×12 | about 10 ft |
Estimates for planning only — confirm load-bearing beams with a professional.
FAQ
Can I use a beam span table for any species of lumber? No, span tables are specific to a species and grade of lumber (or engineered lumber product) because bending strength and stiffness vary significantly between species, so always confirm the table matches the actual material being used.
See the Joist Span Chart and the Header Span Chart.
What affects beam spans
The distance a beam can span depends on the size and grade of the lumber, the load it carries, and how much floor or roof area bears on it. Deeper beams span farther than shallow ones, and engineered lumber such as laminated veneer lumber often spans farther than solid sawn lumber of the same depth.
Using the chart safely
The values are typical for stated assumptions, so check that your loads, species, and grade match them. Beams also need enough bearing length at each end and a solid load path down to the foundation. A built up beam must be fastened together as the tables require. Confirm the design with your local building code or a structural engineer.