How To Build a Deck Railing…


so it will be sturdy and ensure the safety of your friends and family. Railings are usually required by building code on decks more than 30 inches off the ground. They must be firmly attached to the framing members of the deck and not to the decking material. This page is intended to be a basic guide, contact your local building code enforcement department for guidelines.

The image below is an example of what might be required by your local building codes. The dimensions of your deck may change based on how high off the ground your deck is.

deck railing code

For instance, a deck that is 5 feet 10 inches off the ground or less may require a railing height of 36″. A deck greater than 5 feet 10 inches off the ground may require a railing 42 inches high.

Again, to make sure you are in compliance with your local building codes you will need to contact your local building department. These departments are usually very helpful and I’ve always walked away feeling better about my project knowing I’m doing things the correct way.

Failing to follow your local building codes may cause problems especially when it comes time to sell you home. Upon selling your home a survey drawing is usually required. This survey will show a new deck and if the deck doesn’t show in the city’s records they will know you didn’t get the required building permits.

This may result in problems with the sale of the home in which the city has to come inspect the deck. Best case scenario is you followed proper building codes and have to pay for a permit and inspections. Worst case …If the deck doesn’t follow the correct building codes you may be required to remove or rebuild it at your expense. Just a thought on how-to-build-deck-railing!

Types Of Railings

When it comes to how to build a deck railing, the type you choose should reflect your homes style. Imagine this …driving along a country road, you pass a horse ranch with a fence that parallels the road. The fence has 3 or 4 horizontal rails in between each post and is capped on top with a flat 2 by 6. Well, if you have a low ranch style home, a horizontal railing for your deck may be a good look to consider.

If you live in a Tudor style house with a steep roof, consider closely spaced vertical balusters. See my deck-railing-patterns page for more on style.

Tools and Materials

  • Here’s a list of handyman-tools you’ll need:
  • Tape measure / pencil
  • Combination square
  • Awl
  • Compound miter saw
  • Drill with twist bits (1/8th, 1/4, 1/2 inch, and 1 inch spade)
  • Cordless impact wrench or ratchet wrench
  • Reciprocating saw or circular saw
  • Jig saw with aggressive wood-cutting blade
  • levels (24 & 48 inch)
  • Railing lumber (2 by material according to you plan)
  • lag screws with washers
  • 2 1/2 inch deck screws (I like stainless steel but regular deck screws are OK)

Refer to your deck plan for a more comprehensive materials list.

How To Build A Deck Railing

Posts on most decks are constructed of 4×4 material and connect the railings to the deck. Posts can be installed as part of the deck’s foundation, from a footer, connecting to a framing member, up past the decking material where it becomes the connection points for the rails. Posts can also connect to the rim joist on the outside of a deck. In either case, lag bolts are used so railings are sturdy and firmly attached.

If you’re installing you posts on the outside of your deck, measure and cut 4 x 4 posts using a miter saw or circular saw. The tops should be cut square and the bottoms at a 45° angle. The angle removes the protruding “point” of the 4 x 4 that could cause a hazard especially if the deck is high above the ground and passers-by could run into or catch themselves on it.

Step 1. Drill two 1/4 inch pilot holes on the outside of the post. The first pilot hole should be at least 1.5″ above the 45° angle. The second hole should be 2″ above the first. Once you’ve drilled the pilot holes, counter bore each hole to 1/2″ depth using the 1″ spade bit. See my drill-bit-guide for more info on drill bits.

how to build a deck railing

Step 2. Measure and mark the position of each post around the perimeter of the deck using a combination square. Position each post so the beveled edge is flush with the bottom of the deck. Using a level, ensure the post is plum and mark the location of the lag screws by inserting the awl or nail into the pre-drilled hole to mark the side of the deck.

Step 3. Pre-drill holes in the deck. Remove the post and drill 1/4″ pilot holes into the side of the deck.

Step 4. Attaching the posts to the deck with 3/8″ x 4″ lag screws and washers. Here’s where your impact driver becomes your best friend …place the post in position and drive the lag bolts through the post and into the deck. Don’t forget to plan on a post on the outside edge of each stair stringer.

deck railing posts

Step 5. Preparing balusters is the next step in how-to-build-deck-railing. Again, this will depend on your deck’s design. A typical deck-railing-pattern design uses 2×2 material mounted vertically. They could be sandwiched in between a top and bottom rail or attached to the top rail and the rim joist that surrounds the perimeter of the deck.

This is easy if you purchase ready-to-install balusters from your local Home Depot or Lowes. They sell bundles of 2×2′s with ends already cut on a 45° angle. These balusters are screwed vertically into top and bottom rails about 4″ apart from one another.

Deck Railing Baulusters

If you plan to make you own, measure and cut them using a miter-saw. You can use a circular saw but a miter-saw will make quick work of a tedious job. Be sure to pre-drill the holes to prevent the deck screws from splitting the balusters.

The how-to-build-deck-railing option that is pictured on the left side of the image above is sandwiched between the top and bottom rail. Construct the railing and balusters using the deck as a work surface then attach the whole assembly to the posts. For the option on the right, attached the top rail around the perimeter of the deck and then simply screw each baluster in individually.

Step 6. Stairways: Measure from the top of the decking material to the top of the upper stairway post. That measurement will be the same as the other rails. Transfer that measurement to the post on the bottom of the stairs.

Step 7. Position Railing against the posts at the top and bottom of the stairs with the top edge aligned with your pencil marks and clamp it in place. Mark the outline of the post and deck railing on top of the stair railing. Mark a diagonal line across the tops of each post using the railing as a guide. Now you’re ready to make your cuts. A reciprocating saw is excellent for making the cuts in the post and a jig saw for the stair railing.

Deck stair railing

How-to-build-deck-railing… using round metal balusters

Home centers always have great looking accessories that look good and make the job easier as well. I used a round metal baluster for my deck. They require a special mounting hardware package that makes installation a snap.

Line up your top and bottom rails on a couple of saw horses or a workbench. Find the middle …if your posts are spaced 6′ apart the center of your rails should be 3′. Mark the center point. Spacing the balusters is easy. I like to cut a 4″ spacer block to make my marks faster. Simply work out from the middle to each end marking both top and bottom rails as you go. Now you’ve got evenly spaced marks on the top and bottom rails and you’re ready to mount the balusters.

Round Metal Balusters

That’s how to build a deck railing. For more information on decks… check out these pages:

Deck Railing PatternsDeck RepairHow To Clean A Deck