How Do I Finish the Inside Frame of Newly Installed Windows?

Level

• You cannot do any of your other finishing work on your window installation until you make sure the interior is level. Even though you spent time leveling your window on the outside, it can still require some work on the inside to make sure it is completely level. A properly leveled window will help to keep water out of your walls and prevent the build-up of mold. A leveled window frame also makes moving the window up and down easier. Use a level on each side of the window to see how it sits, and then use wooden shims to get the window jamb level. Carefully hammer the shim into place until the jamb is level at that area, and then break the shim off so that it is flush with the wall. Do this on all four sides of the window.

Sealing

• Seal around the window frame with outdoor caulk. Once the caulk has settled, you can use spray foam to help insulate around the window. Give the spray foam a couple of days to completely expand and dry, and then cut away the excess so the insulation is flush with the wall. Not only will the spray insulation help to keep air from flowing around your window, but it will also help the shims hold the window in place.

Trim

• Choose a trim that matches the rest of your room's decor. If you require angled miter cuts to put the trim in place the way you want it, then either rent a power miter saw or purchase one. It can be very difficult to accurately miter cut window trim by hand, so get a power saw to get a more accurate and professional looking cut. Install the window sill first, and then trim around the sill and the window. If you plan on staining or painting your window trim, try to paint or stain the trim before you install it to make the installation cleaner.