How to Anchor Stair Railing With Plaster & Lath

Measure the height placement of the rail first: Go to the top stair and measure up from the stair nosing. Mark the height line with a pencil. The standard height of stair rails is 34 to 36 inches.

Walk down to the bottom stair and measure from the nosing up to the approved rail height. Make a mark with the pencil.

Connect the two height measurements with a chalk line, and snap a line, getting assistance from a helper. The stair rail will be installed along this line.

Use the stud finder to locate the studs behind the plaster and lath walls. Mark the location of each stud with the pencil by marking a vertical line on top of the chalk line you just made.

Lift and temporarily position the top of the stair rail along the chalk line. The top of the rail should be aligned with the chalk like. Mark the wall at the underside of the stair rail at each stud location. Your marks will be angled to correlate with the angled position of the rail on the wall. Remove the rail from the wall.

Place the first stair rail bracket on the wall at your marks. Center the bracket over the stud location and align the top of the bracket with the angled pencil mark. Screw in the first bracket, using 1-1/2-inch wood screws. Continue installing the brackets at the location of the studs and below the angled stair rail pencil marks.

Place the stair rail on top of the brackets. Have your helper hold the rail steady. Place the U-shaped bracket over the nose of the first wall bracket. Screw the U-shaped bracket onto the underside of the stair rail. Screw in additional U-shaped brackets in the same manner.