How to Install Hand Rails for Deck Stairs

Measure the stairs, beginning at the nosing at the top landing and ending at the landing or ground at the bottom of the deck steps. This determines the length of the handrail you need. Handrails must run continuously along the entire length of the stairs.

Select a handrail that is the appropriate size and is made of decay-resistant materials. Check with your local home improvement store or lumberyard to determine whether it has special stock -- special materials with specially molded grips on one side. The handrail must be small enough to be grasped. While laws vary among counties, circular handrails usually must have a diameter between 1 1/2 and 2 inches. Handrails that are not round should have a cross-section width of 2 1/4 inches or less.

Establish the angle at which you will cut the ends of the handrail by placing a board or a 48-inch level on the tread of the stairs. Set a sliding bevel to the appropriate angle on a chop saw, table saw or miter box. Make the cuts for the top and bottom of the handrail.

Arrange the rail along the stairs' treads, marking the spots you will need to cut it to fit between the top and bottom newel posts.

Establish the height of the handrail, as prescribed by building codes in your area. Generally, heights must be between 30 and 38 inches.

Apply a clamp, cramp or wood handscrew, placing it around the newel posts and under the rail at the appropriate height. Tighten the clamp’s jaws, distributing pressure evenly around the post. This will hold the bottom of the rail to the newel post, allowing you to secure the handrail. Use two 2-inch drywall screws to attach the handrail to the newel post by driving each from the underside of the handrail into the newel post.

Attach balusters, sometimes called spindles, to provide additional support for the handrail and to fill the gap. Regulations require that the gap be no more than 4 to 6 inches between the balusters to prevent someone from falling through or to prevent a small child from placing his head through the gap and getting stuck. Use pre-fabricated balusters or square hardwood spindles cut to size. Many manufactured balusters come with wood pins already in the base, making it easy to bore holes into the stairs and fit the balusters into the holes. Use common nails or finishing nails to nail the balusters to the steps. Space balusters evenly and according to local codes.