Building a stair banister requires some knowledge of carpentry, so it may be a challenge for the novice. There are three main parts: newel posts, balusters, or spindles, and the rake rail, or banister. Other considerations are the type of wood, if there will be a volute step (curved) at the bottom, and whether the rail will be to the post or over the post. You also need to be aware of building codes, since these may determine the length of the spindles and the height of the posts. These directions are for a to the post banister.
Set the newell posts, one at the bottom of the stairs (called the starting post) and one at the top. Secure both posts with four screws to the riser, two screws at 2.5 cm (1 inch) and two at 15 cm (6 inches). Counter sink the screw holes 1.2 cm (1/2 inch) and fill the holes with wooden plugs. Because the nose of the step sticks out 3.1 cm (1 1/4 inches), the posts will not be flush with the risers. Fill the spaces with wooden plugs. With all plugs, match the direction of the grain.
Measure the banister for length by laying it on the stairs and marking against the posts. This will ensure the correct angle at the right place. Because the banister is to the post, the banister will be cut flush against the post.
Cut the banister to length.
Clamp the banister to the posts to measure for the spindles.
Mark on the steps for the spindle holes, using 11.2 cm (4 1/2 inch) centres.
Use the plumb bob and plumb from the step up to the banister to mark where to drill the holes. With the plumb bob touching the mark on the step, place another mark on the banister where the string touches. There will be two spindles for each step.
Drill 1.8 cm (3/4 inch) holes in the steps, 1.8 cm (3/4 inch) deep, for each spindle.
Unclamp the banister and turn it upside down on the stairs, and then flip the banister so the end that was at the bottom of the stairs is now at the top. This makes the drilling easier since the angle of the holes will be drilled parallel with the spindles. When the banister is flipped back, the holes will line up.
Drill 1.8 cm (3/4 inch) holes, 3.1 cm (1 1/4 inches) deep. This allows for the spindle to go into the rail and then down into the hole on the step for easy placement.
Clamp the rail, right side up, to the posts and secure with glue and screws.
Put wood glue in each hole on the steps.
Place the spindles. Push each spindle up into the hole in the rail, and then down into the hole on the step.
The tops of the spindles are secured with brads in the crease of the rail on the stair side so the brads are not easily visible.
Do not slide on the banister for twenty-four hours. All parts should be ordered at the same time and from the same company so all parts match. Wood from different suppliers may not look the same. Different fittings can enhance the final product. Goosenecks are used for turns in the banister. A level quarter turn is used for 90 degree turns. Tandem caps are used for support on long banisters. Check local building codes before proceeding.