How far can you span a 2×8 floor joist?

How far can you span a 2×8 floor joist?

Max. Live Load 30 lbs/ft2 (1436 N/m2)

Maximum Span (ft – in)
Nominal Size (inches) Joist Spacing Center to Center (inches) Lumber Grade
2 x 8 12 15′ – 10″
16 14′ – 5″
24 12′ – 4″

Can I use 2×8 for deck boards?

Q: Can I use 2×8 treated lumber as deck boards? A: No, that’s a not a good idea. Lumber wider than 6 inches should not be used as a flat surface. Wide, flat boards have a tendency to pool rain water, which can lead to cupping problems.

How far can a 2X8 span unsupported?

Depending on various factors, the maximum span for a 2×8 floor joist is 16′ 6”. The maximum span for roof rafters is 23′ 9”. For headers, the maximum span is 11′ 2”.

Will a 2X8 span 12?

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.

How far can you cantilever a deck joist?

Most cantilevers have a 3:1 ratio. The most common example of this you will find is a deck that attaches to a house that is 12 feet perpendicularly away from the house. The outer support beam must be no closer to the house than 9 feet (or, no more than 3 feet can hang over the outer beam unsupported).

How wide should the floor joist be for a deck?

Deck Framing. Decks are supported on 4-by-4-inch posts, one in each corner and at least one every 8 feet. The outside edge of the deck is constructed with a board the same width as your joists.

How far can you span a double 2×8 beam?

For example, a double 2×8 beam can span 8-ft.-0 in. when the deck joists are 6 ft. long. When the deck joists are 8 ft. long, the beam can span 7-7. When building a deck with 7-ft. joists, you know the beam can span somewhere between 7-7 and 8-0, but you don’t know exactly where.

How far can a deck beam span?

In general, the maximum span for a 4-by-6 beam is 6 feet between 4-by-4 posts. If you move up to 4-by-8, you’re usually allowed to span up to 10 feet between posts. A 4-by-10 can usually span up to 12 feet between posts.

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