Once the decking is on, it is time to build the guard rail. Hopefully, your posts are all in the correct locations (plumb and true) and are cut to the correct lengths. In most situations, a guard rail has to meet the following conditions:

• At least 36" tall

• No openings greater than 4"
• No horizontal pieces that create a "ladder"

Other than that, there are few other restrictions. Some local historic districts may require that your railing be of a specific type, compatible with the historic railings in the district. If your project happens to be in a locally ordinance historic district, make sure that your proposed rail is approved.

The railing I built is a substantial rail with a 2x6 top cap, 2x4 rails, and 2x2 pickets. I built the rail in three steps - see the image below for a close-up of the rail construction.

First, I measured and cut the 2x4 rails and toe-screwed them into place. These screws simply held them in place until the actual supporting piece was installed. The bottom edge of the bottom rail was 4" from the decking and the top edge of the top rail was 34-1/2" from the decking, This spacing allows for the 2x6 top cap to end up at exactly 36" tall.

Next, I installed the 2x6 top cap, screwing down into the top rail along the length. Installing the top cap at this point created a hard edge against which to install the pickets. If the pickets were installed before the top rail, there would be the possibility that they would not line up consistently against the top rail.

If you are using 2x2 pickets, the actual dimensions are 1-1/2" by 1-1/2", so they should be spaced no more than 4-3/4" apart. measure and mark the locations for the pickets before starting to install them.

Finally, I cut the pickets to length (33-1/2") and added a 45 degree miter at the bottom of each one. The 45 degree miter at the bottom of the pickets is purely decorative - I like the way it lets the edge of the rail define the bottom of the assembly. The pickets on each end of each section were screwed to the posts as well as the rails - they serve as the primary means of attachment for the rail.

Due to the nature of the rail pieces, I predrilled all screw holes to prevent cracking or splitting the pieces.