How Do You Install Aluminum Windows?

aluminum windowsGetting ready to install aluminum windows? One of the biggest benefits of aluminum is that it’s extremely light but very durable. If you’re installing a new aluminum window, there are many steps you’ll need to follow in order for the window to be installed correctly. If you have absolutely no window-installing skills whatsoever, get help from someone who does. They should ideally have an understanding of basic carpentry, including how to check for plumb and square, using shims, measuring a rough opening, and reading a tape measure. According to Bob Vila, here’s what you’ll need to install aluminum windows:

  • Hammer
  • Pliers
  • Level
  • Calculator
  • Adhesive sealant
  • Cotton cloth
  • Self-adhesive flashing
  • Tape measure
  • Caulking gun
  • Utility knife
  • Wooden shims
  • Spray adhesive

Step-by-Step Instructions to Install Aluminum Windows

  1. First, make sure the window is square. To verify square, measure your window diagonally in either direction in the shape of an ‘X’. If the dimensions aren’t completely equal, it means the window isn’t square.
  2. Remove the packaging material from your new aluminum window unit and using a cotton cloth, thoroughly clean the frame. Be sure to check the lock to ensure that it works. While you install your new window, leave it in the locked position.
  3. Use silicone caulk on any noticeable gaps within the framework, ensuring that you’re not sealing the working part of the window.
  4. Determine if your window requires any spray adhesive by checking the owner’s manual. Next, apply a thin spray adhesive coating to the rough opening of the frame taking care not to spray the window’s glass. After the spray adhesive is applied, next apply a 3-inch by 3-inch self-adhesive flashing piece in each corner in the upper frame.
  5. Get the sill pan ready. The sill pan works to deflect water away from your window in order to help prevent any water damage. It’s consists of sheet metal and has three sides. Your window should sit comfortably in the sill pan along the rough opening. Follow the instructions in your manual in order to correctly bend, cut, and size your sill pan. Also, there should be an additional inch in order to accommodate the flashing on the outside area of the rough opening.
  6. Get the rough opening ready, which should ideally be ½ inch to ¾ inch taller and wider than your window frame. Make sure you check the rough opening for square the same as you did for the window. With a bubble level, proceed to check the opening for plumb and level. Plumb is the vertical dimension, while level refers to horizontal. Essentially, none of your measurements should be more than 1/16 inch for every couple of feet of rough opening and should never go beyond 1/8 inch. For reinforcement purposes, the rough opening has two studs. If your rough opening has a building wrap around it, peel it back about 3 inches.
  7. Next, install your sill pan. Thoroughly apply adhesive spray 3 inches from your sill pan’s edge and 6 inches on either side of the rough opening alongside the sill pan. Using your self-adhesive flashing, seal each corner of the sill pan. Cut down the flashing to match the size of the sill pan. Last, attach it to the sill pan and then apply the plastic drain screen if one is provided.
  8. Check the position of your window with its right side out and right side up. Also, check where the weep holes are positioned. If your aluminum window is correctly positioned, the weep holes should be facing outward.
  9. Carefully fit your window into the rough opening and check for plumb and square. If your window isn’t plum or square, adjust the location by using wooden shims until it is plumb and square. Attach your aluminum window to the rough opening by hammering a nail through the fin about 3-7 inches from each corner. Be sure to leave some room so you can adjust your wooden shims again before you permanently nail it down. Once more, check the wooden shims for plumb and square. Once you’re certain that your window is correctly positioned, run a small bead of sealant completely around your shims.
  10. Test your aluminum window to ensure that it opens and closes properly and that the lock works before securing the frame completely.
  11. Maintain a 1/8 inch overhang on either side, install the drip cap correctly on the header. Nail the drip cap to the header and then the seal the fin entirely with spray adhesive, taking care not to spray it anywhere on the glass. Last, apply your self-adhesive flashing along the outside of your window frame while pulling the building wrap over the self-adhesive flashing. Check all the weep holes to make sure they’re not blocked.

Closely inspect the entire aluminum window. If everything looks in order and works properly, your installation is done.

Overall, learning how to install aluminum windows isn’t that difficult and can actually boost the overall value of your property due to their sophisticated design.

Related Resource: Maintain a Finish on an Exterior Door