How to Replace Flanging & Cotter Pins on a Roof

Your roof may see every type of weather and temperature change from direct sunlight to an extreme blizzard. Depending on the type of roof that you have, you may have flange nuts with cotter pins that hold bolts in place along the rooftop. Over time, through various weather conditions and aging, you may need to replace the flange nuts and cotter pins due to rust or as a preventative measure. The removal and installation process will only take a minute or two for each flange nut and cotter pin.

Needle-nose pliers
Wrench

Instructions

- 1
  Locate all of the old cotter pins and flange nuts along the roof.
- 2
  Straighten out the bent ends of the cotter pin by using needle-nose pliers.
- 3
  Pull the cotter pin out of the eyehole in the side of the flange nut. If the cotter pins are stuck, use needle-nose pliers to pull the cotter pin out from the flange nut.
- 4
  Remove the flange nuts from the bolt with a wrench.
- 5
  Replace the old flange nut with a new one and tighten it into place with the wrench.
- 6
  Guide the cotter pin into the eyehole on the flange nut.
- 7
  Bend the ends of the cotter pin down against the flange nut.
- 8
  Repeat for all flange nuts and cotter pins along the roof.

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