Stair banisters provide important structural and safety components to stairs, from simple handrails to complex structures designed for aesthetics and safety. Without a properly installed handrail, a stairway is a potential site for accidents in the home. Hardwood rails such oak and poplar are commonly used for banisters.
Measure the top of the stair to the floor at the bottom of the stairs with a tape measure and add two feet to this measurement. Purchase the appropriate length of handrail at a lumberyard or home improvement store.
Slide a stud finder over the wall about 36 inches over the stairs to locate the stud and mark the locations with masking tape. You must secure banisters to the wood beneath the plaster and drywall in order for the banister to be safe. To meet building code requirements, you must mount the banister 34 to 38 inches above the steps.
Cut a 45-degree mitre on one end of the rail with a mitre saw; lay the rail on the stairs and mark the rail with a pencil where the rail contacts the front stair nosing; this cut is for the short return to the wall. Set your mitre to a 16-degree angle and saw the rail at the mark and cut the opposite angle on the remaining rail piece; this cut is for the horizontal top section.
Cut 2-by-4-inch lumber at the same angle as the railing and screw them into the railing with a drill. Wrap masking tape around the edges of the railing. Put on rubber gloves and apply a thin layer of 90-second epoxy to the ends of both rail sections and hold the pieces together for one minute. Then let the epoxy harden overnight.
Align the top of the handrail to the 36-inch masking tape marks and mark the underside of the banister with a pencil. Center the rail brackets vertically on the studs at the top and bottom of the banister and mark the wall with a pencil for placement of all three holes in each bracket. Probe the wall with a nail to find the centre of the stud and drill 1/8-inch holes, angling the holes slightly toward the centre.
Insert a magnetic bit extension on the drill and screw the bracket into the wall. Set the banister on top of the two brackets and align the top joint with the marks on the tape. Drill holes into the banister and screw the banister to the bracket. Install additional brackets every 48 inches along the railing.