How far can you span a pergola beam?

Although it depends on the species and grade of wood. As per thumb rule, for a pergola beam, 2″×12″ size timber you can span it upto 20 feet, 2×10 can span upto 16 feet, 2×8 can span upto 12 feet, 2×6 can span upto 10 feet and 2×4 can span upto 6 feet.

How far apart should pergola slats be?





You want about 5 in. of space between each slat. One slat at 1-3/4 in.

How far can you span a 2 by 6 on a pergola?

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.

What size should beams be for a pergola?

Beams – 2×8 or larger, depending on size of the pergola. There is one double-beam on each side of the pergola. The beams will hang out approx 12 inches past the edge of the post and will be the support for the rafters. Rafters – 2×6 or 2×8 depending on the size of the pergola.

How far can a 4X8 beam span between posts?

Dimensional Lumber Deck Beam Span Chart

Joist Spans
Douglas Fir-Larch, Hem-Fir, Spruce-Pine-Fir, Redwood, Cedars, Ponderosa Pine, Red Pine 4X6 5′-3″
4X8 7′-0″
4X10 8′-4″
4X12 9′-8″

How far can a 4×4 beam span without support?





The initial sag or deflection will typically increase by as much as 50% over time, even with nothing other than gravity affecting it. By itself, with no load, a 4×4 will span 8 feet without noticeable sag.

How thick should pergola posts be?

A standard pergola will most often use 6 x 6 inch posts for support. A very small pergola may use 4 x 4 inch posts as long as it has less than 4 to 6 feet between posts. As a general rule of thumb the depth of hole you use for your posts should be approximately 1/4 of the height of your post.

How far apart should purlins be spaced on a pergola?

about 3” apart

Rafters are spaced about 24” apart. Purlins are spaced about 3” apart. Will the unit be attached or freestanding? Attached would allow the pergola to attach to a home or building.

How deep should pergola posts be?



Dig holes in the locations for the pergola’s posts, making each hole at least 12 inches in diameter and the depth of one-third the height of one post. If, for example, each post is 12 feet tall, then make each hole 4 feet deep.

How far apart can patio posts be?

Common Post Spacing
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.

How far can a 8X8 beam span without support?

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″.

How far can a 2×12 beam span without support?



A 2×12 (2-by-12) floor joists can span up to 23 feet 3 inches, 2×10 (2-by-10) up to 19 feet 1 inches, 2×8 (2-by-8) up to 15 feet & 2×6 (2-by-6) up to 11 feet 4 inches at 16″ spaced by using southern yellow pine graded as #1 when live load of 30 lbs/ft^2 & dead load of 10 lbs/ ft^2.

What size beam will span 20 feet?

For a 20-foot spans, the wood beam has to be at least 16 inches in depth and 8″ in width (4-2×16) used for residential building or projects.

How far can a 4×6 beam span without support?

A Redwood 4×6 beam should span no more than 6′ between supporting posts.

How far can a beam span without support?

Some manufacturers limit their beams to 60′ due to transportation issues, while others have the capability to manufacture beams up to 80′ long. So, the longest unsupported span possible using LVL would be 80-feet. Typically, though, it is common for a continuous LVL span to be between 20′ and 30′.

How big of a beam do I need to span 10 feet?



Thus, for a 10 foot span, you will need atleast 3-2×8 or 6×8 size of wood beam. For a 10-foot spans, the wood beam has to be at least 8 inches in depth and 6″ in width (3-2×8) used for residential building or projects.

What size beam can span 24 feet?

What size beam to span 24 ft:- as per general thumb rule and guidelines, a 4 nailed 2×18 or 4-2×18 or 8×18 size of wood beam can allow to span 24 feet. Thus, for a 24 foot span, you will need atleast 4-2×18 or 8×18 size of wood beam.

How long can wood beams go without support?

A 2×10 beam – made up of two 2x10s nailed together – can span up to 11′ without support beneath a deck that is 4′ wide. For a more normal-sized deck, the same beam can span 8′, supporting a deck that is 8′ wide.

How much weight can a 2x12x20 hold?

The 2×12’s would hold around 150 pounds per foot x length x spans but then you get into mode of rupture or elastics, dead weight live weight.

What is the maximum length of beam?



As long as you can use prestressed concrete beam there is no limit for beam length.