How much can a 6x8 beam support?
How far can a 6x8 beam go? According to the Western Woods Use Book, 1973 edition of the West Coast Lumbermens Association, a 6x8 beam can hold approximately 8,000 lbs, depending on the type of wood, quality, etc. .
How far will a 6x6 beam span?
What is the maximum span of a 6x6 beam? Each 6x6 beam only spans 12 feet, with 2 of those feet supported by a toggle.
How far can a 6x8 Douglas fir beam span?
According to Western Woods Use Book by West Coast Lumbermen's Association, 1973 edition, a 6x8 beam can support about 8,000 lbs., depending on species of wood, grade, etc. on an 8' span.
20 to 25 feet is a serious span - an 8X8 won't even come close. From contributor P: Figure an inch per foot of span. 20' would require 20", 25' would require 25".
2×10 floor joists can span up to 20'. If you have Spruce-pine-fir lumber, then your span changes to 13' 7” for 16” joist spacing. Redwood can support a 2×10 joist up to 13' – one entire foot less than Southern yellow pine.
For 24 foot span, size of simply supported beam for 2-3 storey residential building, using thumb rule, is about 15″×18″ in which beam width is 12″ and beam depth is 15″, if width will be kept 12″, depth should increased, then beam size 12″×24″ can be used, providing with 4nos of 16mm bar at top, 4nos of 20mm bar at
Max. Live Load 20 lbs/ft2 (956 N/m2)
|Maximum Span (ft - in)|
|Nominal Size (inches)||Rafter Spacing, Center to Center, OC (inches)||Lumber Grade|
|2 x 10||12||27' - 6''|
|24||20' - 9''|
Based on different manufacturers' specifications, the maximum span a 2×8 LVL is from 12' to 15'. Spans are also affected by the species of wood used in the manufacture of the laminated joists, with western woods edging out eastern woods in unsupported span distance.
A 2x6 joist can span anywhere between 8' for Cedar and Redwood to 9' for Pine and Fir at 16" OC. 12" OC yields longer spans, while 24" OC allows shorter spans.
A 6x6 with 12' span can support 2000 lbs. if you assume a conservative 1400psi bending stress. If you do a good job bonding the two members together, your double 6x6 can support more than 4,000 lbs.
Figure B: Example of Calculating Header Size
|Header Size||Maximum Span||Number of Trimmers|
|Double 2×6||4 ft., 0 in.||One|
|Double 2×8||5 ft., 0 in.||Two|
|Double 2×10||6 ft., 2 in.||Two|
|Double 2×12||7 ft., 1 in.||Two|
If you're supposed to use a 4x6 timber, you might not be able to substitute a built-up beam made from two 2x6's. Using built-up beams made from doubled up or tripled up dimensional lumber is an everyday framing method. The most common way to build them is simply nailing them together.
A Redwood 4x6 beam should span no more than 6' between supporting posts.
A double ply beam can span in feet if there is no overhang beyond it. A double 2x12 beam can span 12 feet, a double 2x10 can span 10 feet, and so on.
In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2x8 up to 12 feet; 2x10 to 15 feet and 2x12 to 18 feet. The larger the deck, the larger the joists.