How Far Can A 6×8 Beam Span? (Find Out Now!)

Upgraded Home Team
by Upgraded Home Team

Whether you’re building a deck, house, or any other structure, something you’ll likely need is beams. One of the most common types of beams used in construction is 6×8 beams. If you’re doing the construction yourself, it’s important to know the limits and capabilities of your 6×8 beam.

According to the 1973 edition of the Western Woods Use Book by West Coast Lumbermen’s Association, a 6×8 beam can span up to 8 feet while supporting a maximum of 8,000 pounds. As there are five grades of lumber for each species, the weight it can support will depend on the species of wood and its grade.

There are a ton of variables to account for when calculating the span of your 6×8 beam. In this article, we’re going to answer some of those questions and inform you about the capabilities of your beam.

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How Far Can a 6×8 Beam Span?

As a general rule, a 6×8 beam can span 8 feet while supporting 8000 pounds. The distance that it can span, however, increases with less weight. The distance of the span also increases or decreases with different types of wood. 6×8 beams on decks, for example, usually don’t support as much weight as that of a house.

How Much Weight Can a 6×8 Beam Support?

The amount of weight that a 6×8 beam can support is dependent on the material of the beam and the distance between supports. A 6×8 beam can support 8,000 pounds over an 8-foot span. Therefore, if your total weight is less than 8,000 pounds, your beam doesn’t have to be supported as often.

What is the Span of a 6×8 Beam According to PLF?

In order to answer this question, it’s important that you know a few terms, first.

  • PLF

PLF stands for pounds per linear foot. An 8-foot beam is actually 8 linear feet, which sounds confusing until you understand why this matters. PLF is often used to determine how far a beam can span, including 6×8 beams.

  • Span

Span refers to the total distance in feet and inches that a beam can stretch without support. Saying that a 6×8 beam can span 8 feet while supporting 8,000 pounds means that you will need supports every 8 feet. However, you can stretch the 6×8 beam as far as you want as long as you support it as needed.

  • 6×8 beam

A 6×8 beam is the width and depth of a support beam. Despite having the name of 6×8, this type of beam is actually 5.5 inches wide, and 7.5 inches deep. It’s important to remember these measurements anytime you’re working with wood.

Now that we know what each of the above terms means, we can better understand how PLF relates to the spanning distance of beams. A 6×8 beam that can support 8,000 pounds per 8-foot span can support 1,000 plf. Using these two measurements, it’s possible to better calculate spanning distance.

How Often Does a 6×8 Beam Need to be Supported?

A 6×8 beam needs to be supported in accordance with the material of the beam, and the weight it’s supporting. Using the concept mentioned above regarding PLF and spanning distance, we can calculate how often a beam needs to be supported.

For example, a 6×8 beam made of Redwood No.1 lumber supporting 3,000 pounds needs to be supported every 8 feet. A 6×8 beam made of Douglas Fir No. 2 supporting the same weight can span up to 10.5 feet without support.

A 6×8 beam spanning 8 feet while supporting 8,000 pounds can support 1,000 PLF. Using that calculation, a 6×8 beam of the same material can span nearly 20 feet while supporting 3,000 pounds.

Can Steel Beams Span Farther Than Wood Beams?

Because steel is stronger, sturdier, and can support more weight than wood, steel beams can span farther than wood ones. If you’re building a house and don’t want very many support posts, steel beams are your friend. The composition of steel is simply sturdier than that of wood.

Should I Use Steel Beams or Wood Beams When Building a House?

The type of material that you use for your house is dependent on what your goals are. Steel beams are stronger than wood ones which means you won’t have to support them as often. Steel beams can span farther than wood ones which will save money on supporting posts and columns.

On the other hand, steel is also more expensive than wood. While you might save money with fewer supports, those savings will quickly be lost by the cost of the steel. Overall, however, steel beams are longer lasting and less prone to damage than wooden beams.

Related Questions

What are 6×8 beams mostly used for?

6×8 beams are versatile pieces of lumber or steel that can be used for many different things. The most common use, however, is as support beams under a structure such as a floor or ceiling. Basements, roofs, and decks are some of the main areas where they’re used.

Can I calculate the span of a 6×8 beam myself?

While there are many rules of thumb, such as the ones I listed above, for calculating span of a beam, it’s best left to the professionals. Engineers, architects, and contractors have a much better understanding of different types of beams and weight calculation than the general public.

Can I use 6×8 beams as support posts too?

Technically, 6×8 beams can be used as support posts. The downside of using them in this manner in basements is that they’re much bulkier than standard support posts.

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Final Thoughts

As you can see, there’s a lot of calculating that goes into determining the spanning distance of a 6×8 beam. The material of the beam, the weight it’s supporting, and the PLF all have an impact on spanning distance.

If you’re planning to use 6×8 beams for a structure of some sort, make sure that you enlist the help of an engineer or contractor. They have the knowledge and experience necessary to determine the spanning distance of any type of 6×8 beam. They can ensure that you have the right amount of support posts for any amount of weight or type of beam.

Upgraded Home Team
Upgraded Home Team

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