Deck Building 16 - Installing the Railing

A custom deck railing.

Installing the Railings

Margin of Error: 1/4”

Most Common Mistakes

  1. Pickets not plumb
  2. Top railing not level
  3. Pickets not evenly placed
  4. Pickets too far apart

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There are many different styles of railings for decks, and different styles do different things. Choose a style according to your budget, time, and energy, as well as to the overall look and use of the deck. You can incorporate planters, benches, tables, and stairs into your design. A book on deck design or a ride around the neighborhood can give you some inspiration.

I have chosen to teach a rather simple design but one that is often used. If you are building something different from this, many of the procedures outlined here will still apply. If you are copying a design from an existing deck, a close inspection of the deck with sketchbook in hand should enable you to understand how the railing is put together. The main thing you want to be sure of with installing a railing is its stability. There is nothing worse than building the entire deck railing only to discover later that it is weak and unstable and then always worrying whether a guest at your barbeque is going to make an unexpected visit onto your lawn.

There are usually codes that apply to deck railings. If the deck is more than a certain distance from the ground, often 30 inches, a railing may be required. If the deck is closer to the ground, the railing may be optional. Also, the code will allow only a certain gap, four inches to nine inches, between the ballusters, sometimes called spindles, so that a child cannot slip through. The height of the railing is regulated, too—36 inches to 42 inches. Be sure you check all of this before beginning.

The railing we are showing is constructed of 2x2 ballusters with a 2x4 top railing. This is a simple yet attractive design. However, since we are not tying the railing into the foundation posts (which is often the case), stability can be a concern. We will remedy this issue by bolting the bottom of the ballusters to the band joists using two hot-dipped galvanized lag screws, and by tying the railing into the house at several places.

First, cut all the ballusters. For aesthetic reasons, we have cut an angle on the top and bottom of each one. After the ballusters are cut, cut the 2x4 top rail. Try to use pieces that are long enough to span the entire length of each section. If the span is too long and two pieces are needed, you will need to join these two over a 2x4 picket for adequate bearing. Determine where this break should occur for the most balanced appearance. Also, where two sections of the deck come together, miter cut the top rail to cover any exposed end grain. This will look much better aesthetically.

After all your pieces are cut, it is best to bolt the ballusters to the top rail and then install the entire assembly onto the deck. Mark the top rail before fastening so that the ballusters will be property spaced. Then, bolt the ballusters to the rail using lag screws that are as long as possible without poking through the back side of the railing (about 2 1/2 inches). Be sure that your marks are correct and that the ballusters are attached to the proper side. A balluster that is off will show clearly once installed.

Installation is done by using two more lag screws at the base where the picket m At the bottom of each balluster, drill two holes that are one size smaller than the lag screws. This will hold the ballusters to the joists and band. Drill these holes so that they are as far apart as possible, yet at least 1 1/2” from the edge of the band and joists. You are now ready to install the entire assembly onto the deck.

Installation is done by using two more lag screws at the base where the picket meets the joists and band. Again, use 2 1/2-inch lag screws and, as always, be sure they are hot-dip galvanized, aluminum, or stainless steel so they will not rust. It is best to align the balluster/railing assembly so that it is in its exact location and to nail a few ballusters temporarily in place. Then, use a level to locate where each balluster will meet the band and joists. By using the level at each balluster, you can be sure that they will all be level and parallel to each other.

As I said before, uneven ballusters are easily noticed at this stage. It is imperative that the assembly be in its exact location before you start leveling the ballusters. If you need to move the assembly even slightly after the pickets are attached at the bottom, the entire assembly will look askew and will need to be redone. Once you have ascertained that it is in its exact location and have leveled your pickets, hold the picket in place while you mark the location of the holes on the band and joists. Drill these holes, again, using a drill bit one size smaller than the shank of the lag screw. Then, bolt the lag screws in using a socket or crescent wrench. Do this around the entire deck until the railings are all in place. Where two railings intersect at their mitered cut railing top, drill pilot holes through one top railing into the other and then nail together with 10d HDG finishing nails, two from one direction and one from the other. Your railings should now be complete.