How to Replace Aluminum Casement Windows

What You'll Need
Window and all its components
Cats paw
Power drill with drill bits
Bubble level
Water seal gasket or adhesive backed aluminum tape
Nails and screws
Nail gun
Siding or shingles for exterior

An aluminum casement window is a type of window found in many older homes. Aluminum is used as the outside casement or exterior material to the window. The window operates so that it allows air in from the left to right or right to left, rather than by pushing the window upwards. You generally see casement windows as part of a row of windows or in hard to reach areas. Below is step-by-step instruction to how to replace aluminum casement windows.

Step 1 – Remove the Existing Window

Remove the molding and the window frame from the inside and the outside using a pry bar. Remove a row of shingles or siding around the exterior of the window. Do this carefully if you intend to use them again.

Step 2 – Remove Exterior Nails

Using a cat’s paw, remove all of the exterior nails holding the window in place, leaving the center top one for last. Your window should now be free and you can tilt it out. Use a helper.

Step 3 – Make Opening Watertight

Use a water seal and a gasket to make the entire window area water tight. You must use the gasket and seal on every side of the window. Start at the bottom and work your way around to the sides and then to the top. The gasket will prevent water from seeping into your home.

Step 4 – Level Opening

Using the level, make sure that your opening is straight. Hanging a window that is off from level will never allow the proper amount of airflow in or it will create a non-airtight seal between the window and the window trim.

Step 5 – Place Window in Opening

Enlist the help of someone else and have them steady the window as you insert it into the window opening. Again, make sure you are placing the window in a level fashion.

Step 6 – Nail the Window

Use your nail gun and nail in the window. The window frame will have a bunch of holes in the flange that overlaps the wall. You need to account for a nail in each and every one of these holes. Check that the window stays level as you nail.

Step 7 – Additional Water Seal

Add another layer of water seal or gasket to the bottom of your window to ensure you have double the amount of protection from water.

Step 8 – Interior Installation

You will need to build out the casing. Once this is completed, you can install all the window hardware.

Step 9 – Finish Work

Your window is now installed and all that remains is the finish work. On the interior, you will need to hang molding and paint the casing and the molding as needed. On the exterior you will need to install a new sill and window frame. Be sure to caulk all openings to further guard against water leakage.

Finally, replace any shingles or siding that were removed.