How to Replace Windows Without Disturbing Siding

Replace your windows from the inside.

Don't let your home's siding hold you back from replacing your windows. Window installations can be done from inside the house, which means your siding will be left undisturbed. You typically spend less time on this sort of installation too. Any window type can be installed from the inside of your home, so replacing your old windows won't be a problem at all.

Things You'll Need

• Eye protection
• Ear protection
• Respirator
• Gloves
• Drop cloths
• Utility knife
• Crowbars
• Hammer
• Cordless drill
• Screw bits
• Sawzall
• Wood shims
• New window(s)
• Stainless steel screws
• Level
• Backer rod insulation
• Non-expanding foam spray
• Chop saw
• Extension cord
• 6- to 8-foot-long table
• Window trim
• 8-penny trim nails
• Silicone

Instructions

1. Put on all protective gear. Lay down drop cloths on the floor under the windows you are working on.

2. Cut away any built up silicone or paint from around the interior window trim, using the utility knife.

3. Remove the interior window trim with a crowbar. Remove any nails holding the trim in place with the hammer. If the trim is screwed to the wall, use the cordless drill and screw bits to remove it.

4. Save any trim you want to use as a template for the new trim.

5. Cut out any window insulation, so you can expose the nailing fin of the window. Use the utility knife to do this.

   The nailing fin is a piece of material that allows the window to be attached to the wall studs.

6. Inspect how your window is attached to the wall studs. If it has a nail fin, cut it out, using a sawzall. Go all the way around the window with the sawzall while a helper holds the window steady.

7. Remove any screws that may be installed through the sides of the frame with the cordless drill and screw bits, if your window has no fin. Nails will have to also be cut with the sawzall.

8. Pull the old window out, being careful not to disturb the outside siding or wall.

9. Measure the rough opening size with a tape measure to make sure your new window will fit.

10. Place a couple of shims on the bottom of the window opening and set the window in place. Install two stainless steel screws, one in each side and level the window as you go. These screws will hold the window in place as you make adjustments.

11. Install more shims and screws and level the window as you work your way around the entire opening. Have a helper hold the window in place if necessary.

12. Install backer rod insulation into the cavity between the wall studs and window frame. Spray in non-expanding foam to cover the smaller spaces.

13. Measure and cut the new trim with a chop saw and long table. Make corner cuts at a 45-degree angle and nail or screw trim to the wall.

14. Apply a bead of silicone around the trim and let dry for several hours.

References

• This Old house: How to Install Replacement Windows

Resources

• Reader's Digest: How to Install Replacement Windows: Plans and Instructions