How to Install a Sister Joist for a Porch Swing

Sister joists are lengths of lumber attached to installed joists. Sister joists are used to strengthen damaged joists, accommodate added weight loads, and shore up cracks due to wear and tear. You can create sister joists using a 2-inch-by-4-inch or larger piece of lumber as long as it spans the main joist. When installing a porch swing, you can strengthen its joist with a sister joist to reduce twisting and bowing.

Tape measure
Sister joist lumber
Carpenter’s square
Circular saw
Construction adhesive
16d nails
Hammer
Safety glasses

Instructions

- 1
  Measure the span of the porch ceiling's joist with a tape measure to determine the length of the sister joist.
- 2
  Transfer the measurement to the lumber and draw a line across it using a carpenter’s square.
- 3
  Cut across the scribed line in the lumber using a circular saw to create the sister joist.
- 4
  Apply a generous amount of construction adhesive to the side of the sister joist that you will press against the main joist. Slip the sister joist next to the ceiling joist you will attach it to.
- 5
  Hammer three evenly spaced 16d nails along the sister joint's butt end and into the main joist. Measure every 16 inches and hammer another three 16d nails up the face of the sister joist into the main joist. Repeat this process across the entire length of the sister joist.

How to Install Vinyl Siding & Skirting

How to Insulate a Concrete Porch Floor

Exterior Remodeling