How to Size a Deck Beam
A beam is a solid structural member that is supported by posts and footings that accepts and transfers the load from joists. Once you know the distance between support posts and the length of the joists that will be supported you can determine the required size by checking our beam-sizing chart. The size of a beam is a function of the amount of weight it must support and the distance it must span.
A common beam is composed of the same size and type of lumber used for the joists by nailing 2 or 3 together side by side. Even if you are allowed to use a smaller beam, you should maintain the same depth of material as the joists to present a uniform appearance. Never position your post “sandwiched” between two boards as is sometimes seen as a beam construction technique. The relationship between directly applied and fastened boards is what bonds the strength of a multiply beam.
Occasionally a beam application may require spanning a long distance that exceeds the design limits for conventional beams. In these cases you may have to use an engineered beam to meet the required load capacities. Engineered beams are fairly expensive, so you might want to add another post to reduce the span if possible. Your local building supplier should be capable to use your plans to determine which size and type of beam will work. Steel I beams are the strongest form of beam available and can be used to carry extremely long spans 20 ft + but are very expensive, heavy and difficult to work with.
How to Decorate Deck Support Columns
Browse some examples of decorative deck support posts for tall decks.
Composite Decking Over Concrete: How to Install & DIY Tips
A concrete porch or patio is very difficult to remove. Laying a deck over concrete is a simple way to add a fresh look to your home. Learn more at Decks.com.
Why is Joist Protection so Important for Your Deck?
If you’ve ever seen a piece of wood left out in the weather for any period of time, you know what happens: decay. Whether through wet rot, insect damage, or mildew, the fibers begin to break down.
Decking Patterns
Installing your decking at a 45-degree angle is a popular style for decks. This can be done to reduce decking seams or just for appearance.
Best Hidden Fasteners for Decking
Hidden fasteners create a clean deck surface and can be used with composite, wood and other materials. Learn about hidden deck fasteners at Decks.com.
Introduction to Decking
Spacing between deck boards provides several critical functions, such as drainage & drying. Learn how to space and stagger deck boards at Decks.com.
More Helpful Resources
Explore Articles by Topic
![Footings](/media/3vsas025/all-articles_footings-2x.png?format=webpg&quality=80)
Footings
Information related to installing frost footings for decks
![Framing](/media/5wrarsgy/all-articles_framing-2x.png?format=webpg&quality=80)
Framing
Learn structural framing methods
![Decking](/media/meljt4np/all-articles_decking-2x.png?format=webpg&quality=80)
Decking
Learn about wood and composite decking materials
![Stairs](/media/2sopl0br/all-articles_stairs-2x.png?format=webpg&quality=80)
Stairs
An in-depth look at the complex issue of how to build stairs
![Railings](/media/hpwbuyzr/all-articles_railings-2x.png?format=webpg&quality=80)
Railings
How to install guardrails and handrails to meet IRC code
![Features](/media/tvcahlmk/all-articles_features-2x.png?format=webpg&quality=80)
Features
An overview on water drainage, benches, planters and lights
![Design](/media/3bvpzvtz/all-articles_design-2x.png?format=webpg&quality=80)
Design
The basics of deck design
![Planning](/media/qdenqrqv/all-articles_planning-2x.png?format=webpg&quality=80)
Planning
Learn about permits and working with contractors
![Porches and Patios](/media/sg5bst1z/all-articles_porches-and-patios-2x.png?format=webpg&quality=80)
Porches & Patios
Build a covered deck to enjoy all seasons
![Ledger](/media/0htjl4uu/all-articles_ledger-2x.png?format=webpg&quality=80)
Ledger
Proper attachment techniques
![Care](/media/qdpnwkry/all-articles_care-2x.png?format=webpg&quality=80)
Care
Maintain your deck to maintain your investment
![Materials](/media/zqfflkeo/all-articles_materials-2x.png?format=webpg&quality=80)
Materials
An overview on water drainage, benches, planters and lights
Why is Joist Protection so Important for Your Deck?
If you’ve ever seen a piece of wood left out in the weather for any period of time, you know what happens: decay. Whether through wet rot, insect damage, or mildew, the fibers begin to break down.
Building Above Ground Pool Decks
Decks constructed around above-ground pools are no different than any other free-standing deck.
How to Build a Freestanding Deck
You may need to build a freestanding deck if you can't attach a ledger board to the house. Learn how to build a self-supporting deck.
How to Install and Fasten Deck Fascia
Installing deck fascia can be easy if you have the proper tools, fasteners, and practical information that you’ll find right here.
Hidden Deck Fastening: 3 Ways to Fasten Your Composite Deck Boards
Hidden deck fasteners are the ideal option for DIY builders looking to hide their hardware, without sacrificing the stability of their deck. From nearly invisible deck plugs to color-matched deck screws, knowing how to choose and install these hidden fasteners is an easy way to level-up your deck project.
Best Hidden Fasteners for Decking
Hidden fasteners create a clean deck surface and can be used with composite, wood and other materials. Learn about hidden deck fasteners at Decks.com.
Explore Articles by Topic
![Footings](/media/3vsas025/all-articles_footings-2x.png?format=webpg&quality=80)
Footings
Information related to installing frost footings for decks
![Framing](/media/5wrarsgy/all-articles_framing-2x.png?format=webpg&quality=80)
Framing
Learn structural framing methods
![Decking](/media/meljt4np/all-articles_decking-2x.png?format=webpg&quality=80)
Decking
Learn about wood and composite decking materials
![Stairs](/media/2sopl0br/all-articles_stairs-2x.png?format=webpg&quality=80)
Stairs
An in-depth look at the complex issue of how to build stairs
![Railings](/media/hpwbuyzr/all-articles_railings-2x.png?format=webpg&quality=80)
Railings
How to install guardrails and handrails to meet IRC code
![Features](/media/tvcahlmk/all-articles_features-2x.png?format=webpg&quality=80)
Features
An overview on water drainage, benches, planters and lights
![Design](/media/3bvpzvtz/all-articles_design-2x.png?format=webpg&quality=80)
Design
The basics of deck design
![Planning](/media/qdenqrqv/all-articles_planning-2x.png?format=webpg&quality=80)
Planning
Learn about permits and working with contractors
![Porches and Patios](/media/sg5bst1z/all-articles_porches-and-patios-2x.png?format=webpg&quality=80)
Porches & Patios
Build a covered deck to enjoy all seasons
![Ledger](/media/0htjl4uu/all-articles_ledger-2x.png?format=webpg&quality=80)
Ledger
Proper attachment techniques
![Care](/media/qdpnwkry/all-articles_care-2x.png?format=webpg&quality=80)
Care
Maintain your deck to maintain your investment
![Materials](/media/zqfflkeo/all-articles_materials-2x.png?format=webpg&quality=80)
Materials
An overview on water drainage, benches, planters and lights