Loading

How to Splice a Deck Beam Over a Support Post

It is always best to use a continuous beam without seams for higher strength. Dimensional lumber is readily available in lengths up to 20’ which should accommodate a seamless beam for most applications. However, if your span is greater than 20’ (like the image below) you will likely need to splice some boards to form a beam. In order to do this you should overlap the individual parts of the beam so they are staggered if possible. It is best to have one continuous board over a post allowing one joint to fall on top of the post. Overlapping seams integrates strength and prevents fracturing along seams throughout the length of the beam. Always split a beam over a post.

Plan ahead and layout the beam on the ground over the footings before installation. For instance you could use 2-2x10x10’s and 2-2x10x20’s to form a 30’ beam with one seam set above two intermediate posts.  You can also use hardware applications like strap ties or nailing plates to further secure the connection. Because these connectors are not particularly attractive you will probably want to conceal them behind fascia or on the interior side of the beam.

In this case we had to splice 2 sections of beam over a center post with a seam. 

 

Screw the first piece of the beam to the notched post.
PinterestSave
Screw the first piece of the beam to the notched post.

When attaching the first half of the beam to the notched 6x6 support post screw through the center of the 2x10.  This will hold the 2x10 in place until you install the second 2x10 piece of the beam.

Use a 1/2
PinterestSave
Use a 1/2

Drill 2 thru holes on the edges of each beam section through the beam and notched 6x6 post.  Align your holes 2" from the top and bottom and edge of the beam.

Take out your socket ratchet.
PinterestSave
Take out your socket ratchet.

Use a socket ratchet to tighten the 1/2" x 6" thrubolts from one side of each beam section through the beam and notched post.  Use washers to protect the beam from overtightening.  You may also use 8" long thrubolts.

A solid connection.
PinterestSave
A solid connection.

This is a finished view of the beam splice over a support post.  Notice how both sections of the beam are level.


Popular Framing Articles
Deck Support Columns

How to Decorate Deck Support Columns

Browse some examples of decorative deck support posts for tall decks.

Deck Framing

Using Shims to Level the Deck Surface

Install shims or notch joist bottom across uneven joists to level your deck surface.

Deck Support Columns

How to Use Shared Load Deck Support Posts

Learn how to support an upper and lower deck using one support post and a larger footing by bolting the lower deck into the side of the post.

Next Step: Decking Articles
Decking Installation

How to Install Decking Over Existing Concrete Slab, Patio, or Porch

Discover the best techniques to build a deck over concrete, ensuring proper drainage and stability, while creating a beautiful outdoor space.

Decking Installation

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.

Decking Installation

Tile decking

Installing tile over a standard deck frame in an exterior environment is a recipe for trouble.

Get more helpful resources delivered right to your inbox

Explore Articles by Topic

Popular Framing Articles
Deck Framing

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.

Deck Framing

Reinforcing Deck Rim or Band Joists

Learn a technique to strengthen your guard rails by installing a double rim joist and adding structural blocking to reduce bounce.

Deck Framing

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.

Next Step: Decking Articles
Decking Installation

What to Consider When Building A Wrap-Around Deck

Looking to add a wrap-around deck to your home but unsure of what the process involves? Check out this guide to learn more about top considerations when building a wrap-around deck.

Decking Installation

Building an Outdoor Space with James DeSantis

Composite decking can not be placed directly on concrete. But a substructure can solve for this. Explore this deck project with James DeSantis

Decking Installation

Anatomy of a Deck

A comprehensive guide to help you learn the names and understand the functions of every part of your deck.

Get more helpful resources delivered right to your inbox

Explore Articles by Topic