I recently got a question about how the trim work is handled inside and outside when wood windows are replaced with vinyl and there is a lot of wood rot involved. This is a great question, because it gives me the opportunity to talk about the two types of window installation available — full frame and insert.
This should make it clear for anyone who has ever wondered how windows are installed!
A full frame installation means that all of the interior trim and the exterior trim is removed, including the rotten areas, as well as the buck frame with all its sashes. We are left with what is called the “rough opening.” That’s the window opening down to the two by fours. A custom-built window is then installed in that opening and with that custom-built window comes all new exterior and interior trim.
In other words, in a full frame installation everything is gutted and replaced – interior, exterior and everything in between. Typically, these days, the exterior trim is a composite material, which means that the exterior trim is will be maintenance-free. The interior trim is typically wood, which can then be painted or stained.
An insert installation or a replacement window application, is by far the most common and the most affordable method. In this case, the interior trim is left alone and the existing buck frame is left in place. Only the two sashes are removed. The exterior trim is left in place – that’s the sill and the brick mold.
If there is rot, however, the sill and the brick mold would have to be cut. But that’s not unusual at all. Most older wood windows do exhibit rot in areas. In this case, once the custom-built insert window is inserted in the existing buck frame, secured with set screws and insulated, some vinyl coated coil stock will be bent into the shape of the sill and the shape of the brick mold and then capped over. This replaces the rotten exterior trim.
As for price…the full frame installation involves more steps, more material, and does take more time, which means it will cost more, about 20% to 25% more.
However, a good window company will send a consultant out to your home to analyze your project, offer design ideas and leave you with a written price quote — not an estimate but a written quote — so that you know exactly what the project is going to cost, be it full frame or insert. Regardless of which installation turns out to be right for you and your home, you can be assured of this — you will be getting a beautiful, brand-new window to enjoy for many years to come!