So you've been shopping around for new house windows or commercial windows, and you've finally chosen Pella windows. Pella manufactures great quality and fairly easy to install windows, especially with these tips for installation:
- To install a Pella window, first verify that your opening is the correct size for the window and that it is plumb, level, and square. The correct opening size is usually indicated by a sticker on the window. Make sure you have all the parts before you get started.
- Next, install pan flashing to the sill of the opening. This is six to nine inch wide rubberized tape installed in such a way that water from condensation will flow outside from under the window rather than being trapped in the wall.
- Now, remove the packaging material and fold the integral nailing fin 90 degrees from the jamb (if equipped).
- With a helper, heft the window into the wall opening. As your helper holds it from falling out on the outside, go inside and verify that the it is level horizontally and that it is centered in the opening. Shim as needed to level it. Once level, two roofing nails can be pounded through the nailing fin at the bottom to hold the windows from shifting.
The person outside should now check to verify that the window is square. To do this, measure the diagonal distances between corners. If the numbers match, it is square. If not, shim as needed to make it square.
Once the window is square, the nailing can be completed. As the outside person nails, the inside person should verify that the jamb of it is flush to the interior finished wall surface. Nail spacing should be about every 6". Now is a good time to verify that the window operates as expected.
- Next, the window flashing should be completed. A drip cap must be installed at this point. This is a piece of metal with two opposite bends that is installed at the top of the window to prevent water from entering. Caulk is not an alternative to this step. Cut the cap with tin snips to match the width of the window and use roofing nails to attach it to the wall. Next, apply wrap tape to the sides (overlapping the piece used at the pan flashing stage). And finally, apply a length of wrap tape to the top of the window - over the cap and overlapping the two side pieces of tape.
- The window is now completely installed and ready for interior trim and exterior siding. Now you know how to install a replacement Pella window, enjoy it!