Installing windows is very important,  Unfortunately, when a problem arises after you have your windows done you will call the window company, they tell you to call the contractor and then when you call the contractor they tell you that they just install windows and to call the window company.  Do yourself a big favor, whoever you decide to purchase your new windows from make sure it’s with a full service window dealer, someone who you can report with directly and not have to worry about subcontractors. With that in mind, improper installation will cause 51% of all problems with windows and 49% will be product failure. 

In addition, whoever puts the windows in for you, make sure they’re doing it the right way and I will tell you how it’s done, there is only two ways.  The first way is with the nail flange (or without, it doesn’t matter if it has one or not)).  Now when these windows are installed, this is what they will have to do:

The first thing that happens is the installers have to come out to the house and cut back your beautiful wood (vinyl, aluminum, etc.) siding two to four inches around the entire frame of the outside of your window.  They pull out the old windows and they slide the new windows into the home from the outside.  The nail flange hits the outside of the wall, where you then nail it to the outside and cover it up with wood trim.  After this step, the next part is to cut the liners two to four inches on the inside.  This is done in order to keep the window fully supported. 

Now, these frames vary in widths, depending on the manufacturer, they will be anywhere from three to six inches in total width.  From the nail flange to the inside is about two to four inches.  Now if you have aluminum frame windows (that is what you probably have) they aren’t that wide.  If you were to measure them they’re about two and a quarter inches in width (that is universal).  So to insure that these windows are fully supported by the frame of the house, what they have to do is cut back your window seal liners two to four inches on the inside of your home. 

The bad part about this type of installation is a lot of people don’t like to see the entire window frame.  When you install it this way you lose a lot of sill space and if you have mini-blinds a lot of times there’s not enough room to put them back up.  Because the nail flange hits the outside wall and causes this, they nail it to the exterior surface and then they cover it up with wood trim around all four sides.

Some people don’t like that type of installation.  They don’t want to have their siding cutback on the outside and they don’t want to have their liners cut back two to four inches.  They also don’t want to lose their window seal space and if you he mini-blinds space, most of the time there’s not enough room left to remount the hardware so you will have to go to wall-mounted blinds, I will tell you that wall mounted blinds are not cheap.  They are just as expensive as new vinyl windows.

Every window that is installed comes with a manufacturers installation.  It’s very important that when installing windows you do it the right way.  If you don’t it will void the warranty (read fine print). 

In construction, contractors take shortcuts all the time.  You can’t do that with vinyl frame windows.  It causes problems, years ago manufacturers got tired of being held responsible for everything so they started putting window stickers on the front and back of their windows showing exactly how to install them.  I don’t have a whole installation guide because each window manufacturers guidelines are different.  Here is what to remember in a nutshell.  Do not use expanding foam use caulking.  Make sure to use caulking that expands and contracts with the weather temperature.  Install level, plumb, and square on all four sides.  Do not store or keep windows out in the sun because this will cause them to warp and sag.  Do not nail headers, if you change or alter the frame or do anything listed above, it will void the manufacturer’s warranty making it so you will have problems in the future with your windows.

The second way it can be done is retro-fit, which means fitting the new window into the existing structure, which uses the existing structure of your aluminum frame windows.  This window is usually Euro-Vinyl window.  Euro-Vinyl lasts a minimum of 40 years and fully supports the structure of the window on two and a quarter inches (see article Energy Savings From Windows).  The new window is designed to be an exact replacement for the old window.  You do not lose your siding and there’s no wood trim to paint.  Some people find it hard to match the wood trim to the siding of their home.  Another plus is the new window feels like it was always a part of the home.  Since it has four inch screws screwed in all four sides of the window frame into the stud frames of the wall.  When you install the other way (above), the new windows end up having a ½ inch gape (usually), which makes it look like the window is floating outside. 

No matter what way you have your windows installed make sure they are done right and correct by a knowledgeable contractor or company with experience in the industry.  Thinking about all the different ways and how big the frame of windows are makes a difference on installation.  It will also make the whole experience enjoyable if you don’t have go back and discover that your window seal space is taken up by the window frames (see article Energy Efficient Windows Warranties).