The maximum span of 2×8 ceiling joists without support depends on several factors, including the species and grade of the wood, the spacing of the joists, the live and dead loads the ceiling will bear, and local building codes.

However, as a rough guideline: Common Species and Grade of Lumber (e.g., Douglas Fir-Larch, Southern Pine):

In general, for 2×8 ceiling joists spaced 16 inches on center (16″ o.c.), the maximum span is typically around 21 to 23 feet while

joists spaced 24 inches on center (24″ o.c.), the maximum span is usually around 18 to 20 feet. If you use a stronger species or grade of lumber, you might achieve a slightly longer span.

There are different species of 2×8 lumber of grade -1 and grade -2 are used as ceiling joist like Hem Fir (HF), Spruce pine fir (SPF), Douglas fir & larch (DFL) and Southern yellow pine (SYP). This article describe about how far can a 2×8 ceiling joist span without support and 2×8 ceiling joist span chart.

There are different depth of ceiling joist are used in floor construction such as 2×4, 2×6, 2×8 and 2×10 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.

Ceiling joists provide support for more than one surface in your home. The first surface is, unsurprisingly, the ceiling, the materials of which attach directly to the joists. The other surfaces are the walls, which the joists span the distance between, providing a source of support to keep the walls from shifting.

Ceiling Joists are technically beams that typically spans relatively short distances compared to beams and are made of wood, steel, or engineered wood or lumber.

Spacing between ceiling 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.

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**How far can a 2×8 ceiling joist span without support**

How far apart ceiling joist can maximum span will depend on load condition, slope, wood species, grade of lumber, climatic condition, locality where you live, building codes and design of structure.

In general, a 2×8 ceiling joist can span from 21 to 23 feet at 16″ oc, 24 to 27 feet at 12″ oc, or 18 to 20 feet at 24″ without support.

A 2×8 Southern yellow pine (SYP) grade #1 ceiling joist can span a maximum of 23 feet and 10 inches far apart from beam to beam at 16″ spacing, or 26′- 2” at 12” spacing, or 20′-10″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Southern yellow pine (SYP) grade #2 ceiling joist can span a maximum of 23 feet and 4 inches far apart from beam to beam at 16″ spacing, or 25′- 8” at 12” spacing, or 20′-1″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Douglas fir& larch (DFL) grade #1 ceiling joist can span a maximum of 23 feet and 10 inches far apart from beam to beam at 16″ spacing, or 26′- 2” at 12” spacing, or 20′-1″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Douglas fir& larch (DFL) grade #2 ceiling joist can span a maximum of 23 feet and 0 inches far apart from beam to beam at 16″ spacing, or 25′- 8” at 12” spacing, or 18′-9″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Spruce pine fir (SPF) grade #1 ceiling joist can span a maximum of 22 feet and 4 inches far apart from beam to beam at 16″ spacing, or 24′- 7” at 12” spacing, or 18′-9″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Spruce pine fir (SPF) grade #2 ceiling joist can span a maximum of 24 feet and 4 inches far apart from beam to beam at 16″ spacing, or 27′- 7” at 12” spacing, or 18′-9″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Hem fir (HF) grade #1 ceiling joist can span a maximum of 22 feet and 10 inches far apart from beam to beam at 16″ spacing, or 25′- 2” at 12” spacing, or 19’-7″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

A 2×8 Hem fir (HF) grade #2 ceiling joist can span a maximum of 21 feet and 9 inches far apart from beam to beam at 16″ spacing, or 24′- 9” at 12” spacing, or 18′-6″ at 24″ spacing without support with a maximum ceiling loads are assumed to be 15psf.

**How far can a 2×6 ceiling joist span without support**

**How far can a 2×4 ceiling joist span without support**

**How far can a 2×10 ceiling joist span without support**

**How far can a 2×8 ceiling joist span without support**

**What is the maximum span of a 2×12 floor joist?**

**Conclusions:-**

A #2-SYP 2×8 ceiling joist can span a maximum of 23 feet and 4 inches at 16″ spacing. For the same size joist, grade and spacing, SPF can allow to span 22′-4″.