How to Install Deck Railing Posts [3 Easy Steps]

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how to install deck railing posts

Installing an outdoor deck in your backyard is a great way to add some outdoor space to your home. 

Taking the time to make sure your deck is safe and secure is essential. While building it can be a fun project, it is most important that you and your family are safe. 

To make sure your deck is safe, you will want to install a deck railing. This will give people something to lean on and make sure no one falls off. 

Establishing this perimeter can help mark off where the deck ends. If you properly install your deck railing posts, you can keep your deck safe and make it look finished

In this article, we have laid out how to install deck railing posts. Following these steps will help you do a quality job. 

Installing Deck Railing Posts: Basic Idea

Installing deck railing posts is a relatively simple job. Having the right materials and measuring carefully will help make it a success. 

The steps to installing deck railing posts include: 

  • Get Materials 
  • Cut the Posts to Size
  • Cut Post Notches 
  • Bolt on Posts 

Why Install Deck Railing Posts?

why install deck railing posts

If you have a backyard deck, it can be a great addition to your home. However, without railings along the perimeter, it could be a safety hazard. 

In fact, oftentimes, it will be against your local municipal codes to not have railings. 

If you don’t have them, you could be subject to steep fines and zoning violations. Check with your local assessor’s office to see what the regulations are in your area. 

You should also install deck railing posts because they give your deck a finished look. 

Having railings around your deck will enclose the area. It will also give you an opportunity for more stylistic choices. 

If you want to add more decorative elements like wicker or lighting, railings can help with that. 

Gather Materials 

The first thing you should do when starting your deck railing post project is to gather the materials. 

To do this project, you will need: 

  • 4×4 posts 
  • Circular saw 
  • Measuring tape 
  • Pencil 
  • Carriage bolts 
  • Washers
  • Nuts

By having all of your materials beforehand, you won’t have to go back and forth between the hardware store. 

Cut the Posts 

The length of your posts will be the height that you want your railing to be at. 

If you want to include caps on the tops of your rails, you should add enough space at the top. However, check with your local municipality or homeowner’s association to see what the max height is. 

If you don’t want to use rail caps, you can cut the tops of the posts at an angle. This will give you a little bit of a decorative touch. 

The tops of the railings are where you can use your creativity. There are many options for lighting and ornamental touches. 

Drill two holes in the posts that are 1 ½” from the bottom and top of the deck joists. These will be where you attach the posts to the joists. 

Cut Notches in the Deck 

Your deck’s planks probably hang slightly over the edge of the deck above the joists. 

Because of this, you will need to cut notches in the planks. This will allow the posts to sit flush against the joists so you can secure them. 

For 4×4 deck posts, you should maintain a maximum distance of six feet. 

This will give the railings enough support that you can lean on them without bowing the wood. It will also give you the best possible space for decorative elements. 

You will have to measure out your deck and see what a proper interval will be. This will be based on the distance between each corner. 

Attach Posts 

Once your notches are cut, you can then attach the posts to the deck joists. Drill holes in the joists that align with your post holes. 

Tap the carriage bolts into both holes and slip the washer on the inside. Then, screw the nut onto the back of the bolt. 

Test the strength of your posts to make sure they will be able to take weight. If you have properly measured them and attached them, they should be perfectly suitable.

Frequently Asked Questions 

faq how to install deck railing posts
  • Can I use 2×4 for deck joists?

You can use 2x4s for deck joists. However, they may not be the best option if you plan on having a lot of people on it. 

In those cases, 2x6s may be your best option. 

  • What is a floating deck?

A floating deck is a deck that isn’t attached to a building. 

If your deck is butted up against your house, it is not a floating deck. Floating decks are usually out in gardens or yards as a separate feature. 

  • How much weight can a 2×4 hold?

The amount of weight a 2×4 can hold will depend on many factors. 

A 2×4 that is structurally sound can hold up to 300 pounds. However, it is best not to put more than 100 pounds on any one 2×4 to be safe. 


By installing a deck railing, you can give your deck a finished look. You can also keep people from tripping and falling. 

By following the above steps, you can be sure that your deck railing will be secure no matter what type you have. 

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Michael J. O’Connor is a writer and marketing specialist from the Bay Area of California. A graduate of Sonoma State’s Creative Writing program, he spent many years as a contractor and carpet layer, learning the ins and outs of flooring and general contracting. When he’s not typing away at his desk, he enjoys hiking with his dogs, woodworking and collecting rare books. See full biography here.

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