2x8: They're often used for mid-range floors, such as those in living rooms or dining rooms. They can span up to 10 feet and have a higher load-bearing capacity than 2x6 joists.
“A 2×6 spaced 16 inches apart can span a maximum distance of 13 feet 5 inches when used as a rafter, 10 feet 9 inches when used as a joist, and 6 feet 11 inches when used as a deck beam to support joists with a 6-foot span.”
For sizing the beam, use a joist length of 10' (8'+2') and a posting spacing of 10'. The Beam Size table indicates that the beam may be either two 2x10s or two 2x12s, depending on wood used.
The maximum span of a 2x8 floor joist depends on several factors, including the wood species, grade, spacing between joists, and the expected load. In general, for residential construction using standard framing lumber such as Douglas Fir-Larch, a joist can span approximately 10 to 13 feet when spaced 16 inches apart.
2x8: They're often used for mid-range floors, such as those in living rooms or dining rooms. They can span up to 10 feet and have a higher load-bearing capacity than 2x6 joists.
2x4 11'-6" 2x6 17'-0" 2x8 21'-8" 2x10 25'-7" 24" O.C.
Total header height needs to be 12 inches over a 10' span.
2-by-6 joists:Joists should span 9 1/2′. 2-by-8 joists:Joists should span 13′. 2-by-10 joists:Joists should span 16 1/2′.
For example, a 2x6 joist would have a 12-foot, 6-inch maximum span, and a 2x10 joist would have a 21-foot maximum span.
For instance, a double 2×12 beam can span 12 feet; a (2) 2×10 can span 10 feet and so on.
For best long-term durability, use pressure treated lumber as floor joists in your storage shed. If you want the strongest floor joists to hold the highest weight capacity, select 2x6 floor joists in your storage shed. For average storage use, 2x4 16" O/C is a standard floor joists with good strength.
A 2x6 floor joist can typically span up to 12 feet and 6 inches without support. However, the distance a joist can span depends on several factors, including the spacing of the joists and the type of wood used: Spacing: For example, a 2x6 redwood or cedar joist can span eight feet if spaced 16 inches apart.
It depends on your beam span. For a beam span of 11 ft, the joists can only span 6 ft. If the beam span is decreased to 8 ft, the joists can span 12 ft. And 2x8 joists can span a max of 13 ft, so that pretty much covers it.
The span of a 2x6 deck joist depends on your deck joist spacing and material. For instance, a 2x6 redwood or cedar joist can span eight feet at a spacing of 16 inches. On the other hand, a 2x6, 16- or 18-gauge steel joist can span 16 feet, 4 inches if the spacing is 12 inches.
Deck joist flashing tape is an affordable and effective way to protect your deck's wood substructure. 1. It helps prevent moisture penetration 2. Helps protect lumber from rot 3.
It really all depends on the loads. I have built porches with 2x6s on 8 ft spans 16 inch OC. If you put the crown up it supports people and patio furniture just fine. However, like I said, a 2x8 will deflect less initially and over time so going with a 2x8 may be desirable.
Most composite decking materials, like Trex composite decking, limit maximum joist spacing for composite decking to 16" on center spacing for straight decking and 12" on center joist spacing for 45-degree angle diagonal decking.
If the outside edge of your deck is at least 17” above grade, a double 2x8 deck beam should be installed to support the joists along the outside.
However, a general guideline for residential construction is as follows: For a typical residential floor load (40 psf live load and 10 psf dead load): - A single LVL beam with a width of 1 ¾" can span approximately 10 feet.
Of course, the plywood does add some strength, but for several reasons engineers almost never count on this strength in their designs. Only the layers of plywood with the grain oriented horizontally (parallel with the direction of the header) are really adding any strength.
For residential floor joists made from Southern Yellow Pine or Douglas Fir, a 2×8 can typically span 8 to 10 feet and carry 40 to 50 pounds per square foot of live load. For ceiling joists or roof rafters, a 2×8 may carry about 10 to 15 pounds per square foot of dead load, depending on the span and wood species.
On BestDeckSite, we recommend installing blocking on 2x8 joists too. Here's a word of caution. As you get on a roll calling out numbers for the guy at the saw while hammering in the preceding block, make sure not to throw off the joist spacing.