Retrofit window installation is really the easiest of all. The retrofit window already comes with an exterior trim attached. That's the flush fin that goes against the outside surface, usually stucco. Prepare the window by drilling 3/8" holes in the areas of the frame where you want to screw it in place. Normally, there will be 3 holes on each side and 3 more across the top. Don't predrill any holes in the bottom track. After removing the old panels, you want to run a heavy bead of caulk on the face of the old aluminum frame that you left in place. Then you and a helper set the bottom of the vinyl window onto the old aluminum bottom track and raise it into position. The flush fin or retrofit lip will act as a "stop" to hold the window in place. Have your helper hold the window while you go inside.
Once inside, you want to center the window in the opening. Slide the vent panel open and closed to make sure the window is plumb and level. To adjust for out of square conditions, shim the bottom right or left corner by placing a shimming material between the sill and bottom of the window frame. Once square, drive a 3" deck screw through the 3/8" holes and into the wood studs.Just seat the screw, don't overtighten. After you get the screws into the sides and top, remove the sliding panel. The bottom track should lift out. Look for drainage holes in the track and insert a thin screwdriver and lift up. Drive one screw in the bottom center, caulk around the screw head, then put the track back in place and re-install the sliding panel. Now, you want to go back outside and caulk the gap where the retrofit fin meets the exterior surface of the house. You want to have a double barrier of protection against water infiltration. Remember, you already applied a generous bead of caulk before inserting the new frame into the opening. The rest of the job is done on the inside.
First, you want to plug the 3/8" screw holes to hide the heads of the screws. We sell the hole plugs on the website. Just click on the "Purchase Trim" tab to see a picture. The plugs will pop into place in the hole. The next step is to fill the gap around the new frame with R-13 Insulation. Do not use the foam insulation that comes in a can. Many manufacturers will not honor the warranty if the foam is used. Even the non expanding foams can cause the frame to distort, causing problems. Pack the insulation in tight. You might want to wear a dust mask during this procedure. Many people, myself included, are very sensitive to insulation. After the insulation is in place, you want to install trim around the inside to finish the job. You can use wood trim from the hardware store, or some other product. But in my experience, the best product is a vinyl flat trim that matches the window frame. The flat trim can also be purchased on the website under the "Purchase Trim" tab, or you could try to find it from a local window contractor. Ours comes in 2 different widths, although the 1 3/4" wide piece is by far the most common. The trim has a double sided adhesive tape on the back. You cut the top and bottom first, stick them on the vinyl frame, making sure the trim goes to the drywall. This covers all the insulation and the old metal frame. Do the side pieces next. The final step is to caulk where the trim meets the walls.
Much of the installation process for a replacement frame is the same as the retrofit frame. But, there are a few differences. When you put the new window into the opening using a replacement frame, you don't have the flush fin holding the frame in place. You and your helper have to hold the frame in place while you put a screw in the top center to support the frame. Then, you can do your adjusting for a square condition. All of the procedures on the inside will be exactly the same, from hole plugs, to insulation, to trim and caulk. The outside is different. You have to apply the trim that was part of the retrofit frame. Again, I prefer the flat trim. Once again, you apply a bead of caulk to the old frame,then measure and cut the top and bottom trim pieces. Apply the adhesive part of the trim to the vinyl frame, and let the other part contact the bead of caulk. Trim all four sides, then caulk again where the trim meets the exterior material.
As you can see, it really doesn't matter if the exterior of your home is brick, stone, siding, or stucco. You can install vinyl windows without having to damage the surrounding structure. We have step by step instructional videos for sale on the website at How To Install Windows
