Engineered Deck Beam
It is possible to increase your beam spans and eliminate footings and structural posts for your deck by using engineered laminated beams, heavy timbers or steel I girder beams. Using an engineered beam will reduce the number of posts blocking windows under a deck or may provide a clear span for a deck over a driveway. These beams are designed much stronger and more stable than standard dimensional lumber beams. It is possible to achieve spans up to 20 feet. Engineered beams must be treated for use outdoors.
Glulam beams are manufactured by gluing layers of dimensional lumber together. Parallam beams are manufactured by gluing together aligned wood stands and bonding them using a microwave process.
Large, solid sawn lumber timbers, referred to as “heavy timber” are available, but may be expensive to obtain in decay-resistant species if desired or necessary.
Your local lumberyard should be able to help you size and order engineered deck beams. Bring them a plan of your deck with dimensions showing the position of all your footings and posts. They will send your information to a design center where an engineer will specify the proper size engineered beam. They will also provide a report which will be useful in applying for building permits. Engineered beams are more expensive than standard deck framing materials but are usually the only option for projects that demand long beam spans.
Glue Laminated Timber Beams Spans
Joist Spans | |||||||||
---|---|---|---|---|---|---|---|---|---|
Stress Class | Width | Depth | 6' | 8' | 10' | 12' | 14' | 16' | 18' |
Balanced or Unbalanced 20F -1.5E And Higher Grade Cedar | 3-1/2" | 9-1/2" | 12'-2" | 10'-6" | 9'-4" | 8'-6' | 7'-10' | 7'-4" | 6'-11" |
11-7/8" | 15'-2" | 13'-1" | 11'-8" | 10'-8" | 9'-10" | 9'-2" | 8'-8" | ||
16" | 17'-10" | 15'-5" | 13'-9" | 12'-7" | 11'-7" | 10'-10" | 10'-2" | ||
5-1/4" | 9-1/2" | 18'-0" | 16'-8" | 14'-10" | 13'-7" | 12'-6" | 11'-8" | 11'-0" | |
11-7/8' | 18'-0" | 18'-0" | 17'-6" | 15'-11" | 14'-9" | 13'-9" | 13'-0" | ||
16" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 16'-10" | 15'-9" | 14'-10" | ||
Unbalanced 24F - 1.8E Douglas Fir - Larch or Southern Pine | 3-1/2" | 9-1/2" | 13'-11" | 12'-1" | 10'-9" | 9'-10" | 9'-1" | 8'-6" | 8'-0" |
11-7/8" | 17'-5" | 15'-1" | 13'-5" | 12'-3" | 11'-4" | 10'-7" | 10'-0" | ||
14" | 18'-0" | 17'-9" | 15'-10" | 14'-5" | 13'-4" | 12'-6" | 11'-9" | ||
5-1/4' | 9-1/2" | 18'-0" | 18'-0" | 17'-1" | 15'-7" | 14'-5" | 13'-6" | 12'-8" | |
11-7/8" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 17'-0" | 15'-10" | 14'-11" | ||
16" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 17'-0" | ||
Balanced 24F - 1.8E Douglas Fir - Larch or Southern Pine | 3-1/2" | 9-1/2" | 13'-11" | 12'-7" | 11'-8" | 11'-0" | 10'-5" | 9'-11" | 9'-7" |
11-7/8" | 17'-5" | 15'-10" | 14'-8" | 13'-9" | 13'-1" | 12'-6" | 12'-0" | ||
14" | 18'-0" | 18'-0" | 17'-4" | 16'-3" | 15'-5" | 14'-9" | 14'-2" | ||
5-1/4" | 9-1/2" | 18'-0" | 18'-0" | 17'-4" | 16'-3" | 15'-5" | 14'-9" | 14'-2" | |
11-7/8" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 17'-6' | 16'-9" | ||
16" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 18'-0" | 18'-0" |
Assumes 40 psf live load, 10 psf dead load, L/360 simple span beam deflection limit, cantilever length/180 deflection limit. Glued laminated timber shall be naturally durable or preservative treated with an oil-borne treatment in accordance with AWPA U1.
How to Decorate Deck Support Columns
Browse some examples of decorative deck support posts for tall decks.
Building a Round or Curved Deck
Learn how to build a curved deck using standard wood-framing materials. Composite decking material is more flexible for curved decks than wood.
Decks vs Patios: Cost, Pros, Cons, & Comparisons
Learn what factors affect the costs of decking and patios. Discover all the comparisons factors to help you choose the right space for your home with Decks.com.
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.
Dos & Don'ts for Homeowners to Consider When Building a Deck
Your dream deck can take whatever shape you like. The trick is making it fit your budget and site conditions. While the deck doesn’t have to be built as a rectangle, there could be good reasons for doing just that.
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.
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.
Framing a Deck Parallel to a House
Learn about an alternative framing method that allows you to install your decking perpendicular to the house and makes the deck free standing.
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.
6 Best Alternatives to Wooden Decking
While wood decking was previously considered the standard material for building a deck, that’s changed. Homeowners have been exploring and embracing different types of materials, and the availability of alternative decking materials has grown significantly.
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.
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