How far can I joist span without support?

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”.

How far can a 2×10 I joist span?

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 an engineered I joist span?

Joists are available in several depths and lengths and superior strength allows them to span up to 30 feet (TRIFORCE span tables).

What is the maximum span of an I joist?

Span refers to the length of the I-joist. The L/480 table with a 40 per square foot live load and a 20 per square foot dead load with a depth of 11 7/8 inches will give you spans according to joint weight. With these factors, the lightest joist will have a maximum span of 17 feet, 8 inches.

Will a 2×10 span 14 feet?

An SYP (Southern Yellow Pine) 2×10 lumber span can reach up to 14′ when used as a joist with 16” spacing. If using SPF or Redwood lumber, then the span maximum for the same distances will be half to a full foot less.

Are engineered joists stronger?

Even though they are lighter than 2x10s, engineered joists stronger and more solid. Besides that, engineered floor joists give you more of a surface area to hammer in nails making the job that much easier.

What is the strongest floor joist?

Lumber Grade Since knots and other defects weaken wood, higher grades of lumber (designated as clear, select, or #1) are considered stronger than lower grades. Higher grades of lumber, however, are also much more expensive. Lumber graded as #2 is the most common choice for floor joists and other framing lumber.