How to Replace Aluminum Windows on an Old Trailer House

Most older trailer house windows are flush-mounted.

This means that the aluminum window frame mounts directly to the exterior skin. The windows secure to the trailer with clutch screws. These screws have a special head design that often requires a special bit to remove. The bits or drivers for these types of screws are available at mobile home supply centers where you purchase your windows. Replacing the aluminum window requires removing the old window first and measuring the opening. Purchase a 25-foot roll of putty tape at the mobile home center when you purchase the window. Home improvement centers do not carry the putty tape rolls.

Position a stepladder under the window you are replacing. Remove the screws securing the aluminum window frame to the trailer with a clutch-head nut driver or clutch-head bit adapter in a cordless screwdriver. Start at the bottom of the window frame and then the two sides, leaving the top for last. Ask a friend to hold the window in place as you remove the upper screws.

Insert a putty knife between the aluminum window frame and the side of the trailer at one corner of the frame. Pry the top of the window away from the opening. Ask your helper to grasp the sides of the window as you are prying the window away. Set the window to the side and out of your way.

Measure the window opening from left to right and top to bottom with a tape measure. This determines the size of your replacement window. Remove the residual putty tape from the window opening with a putty knife.

Measure each side of the window opening and cut four pieces of putty tape from the roll, using scissors. The putty tape is sticky on both sides, and has paper on both sides to protect the adhesive. Remove the paper from one side of the putty tape and install the tape around the outside of the window opening. Use two pieces of tape on top of each other on the top of the window opening. This helps protect the window opening from leaks during heavy rain.

Remove the paper from the outside of the putty tape around the window opening. Lift the replacement window into the opening with the assistance of your helper. Place a level on the top of the frame to ensure the window is square in the opening. Use shims as necessary between the aluminum frame and window opening to level the window.

Secure the window to the outside of the trailer with new trailer screws and a clutch-head nut driver or clutch-head bit adapter in a cordless screwdriver, starting at the top of the window frame. Secure the entire window frame to the trailer with the trailer screws and appropriate driver.

Apply a bead of silicone caulk around the outside perimeter of the window frame between the frame and the trailer with a caulking gun.

Things You Will Need

  • Stepladder
  • Clutch-head driver
  • Clutch-head bit adapter
  • Cordless screwdriver
  • Putty knife
  • Tape measure
  • Putty tape
  • Scissors
  • Shims
  • Trailer screws
  • Silicone caulk
  • Caulking gun


  • If siding was added to the trailer, remove the siding from around the window opening to expose the window frame fasteners.

About the Author

Kenneth Crawford is a freelance writer with more than 10 years of experience. His work has appeared in both print and online publications, including "The American Chronicle." Crawford holds an associate degree in business administration from Commonwealth College.