In this video, This Old House general contractor Tom Silva explains how to install a stair handrail.
1. Stand 4-foot level on first step and hold it plumb.
2. Mark the level where it meets top of second step.
3. Calculate height of handrail and mounting brackets; mark bracket height on level.
4. Use level to mark bracket height on wall at top and bottom of staircase.
5. Snap chalk line to connect the two wall marks.
6. Using electronic stud finder, mark wall studs at top, middle and bottom of staircase.
7. Drill 7/64 inch-diameter screw pilot holes on chalk line and into studs.
8. Screw the mounting brackets to the wall studs.
9. Cut handrail to length, mitering the ends to 45 degrees.
10. Glue and nail a mitered return to each end of the handrail.
11. Prime and paint, or stain and/or varnish the handrail.
12. Once dry, screw handrail to mounting brackets.