Return to Window Maintenance, Repair and Design Articles

How To Install Insulating and Decorative Window Film

by Jay Harris

Window films are both decorative and functional... plus can add privacy!

The windows in our house do quite a lot for us and often go un-thanked. They shield us from the elements outside and keep us dry during storms; however they also serve as our window to the outside world. Just imagine a house without any windows in it at all - not much fun to think about, eh? But sometimes there's a little "too much window," and an added bit of privacy here and there wouldn't hurt!

Instead of filling your walls with screws and hardware to put up blinds or curtains, why not work with what you have and cover the actual glass itself? That's where window film comes in!

While most folks are familiar with the insulating plastic added onto the glass during the cold winter, that's actually a different animal altogether. The window films we're discussing today apply directly onto the glass and come in a variety of styles, from opaque black (blocking out all the UV and view from inside and outside), to decorative styles like stained glass or bamboo reeds. They all apply in the same fashion: the best part is that they're easily removable, too!

Special installation considerations... the outside temperature and sunlight!!

Decorative window films can be applied year-round,  BUT you will want to avoid placing it during harsh winters when temperatures dip below 40 degrees F, as this will cause the adhesive solution to freeze before it can set. Also, try to not apply it in direct sunlight, as this will cause the applicator solution to evaporate too quickly so it doesn't set up properly.

Installation steps...

Your first task is to measure out your windows. Remember, since you'll only be covering the glass, that's all you'll want to be measuring. Take these measurements and cut out a piece of your window film roll just a bit bigger than needed (I usually add an inch or two to my measurements, just to be safe).  A regular razor blade or box cutter works great, and be sure to use a straight-edge for even cuts. 

If possible, use a carpenter's square (or other guide) when trimming the film so your cut is square... this will allow you to only have to trim two edges when installing the film on the glass!

Next, you'll need to clean your windows and make sure they're looking like new.

You don't have to get them to a shine or anything, but do make sure that any dirt or dust that may have collected on the glass is removed. For this, you can use either water or a generic glass cleaner. To wipe, make sure to use a lint-free rag so that you don't have any excess fuzzies left on the window that towels can sometimes leave behind.

Once the glass has dried, get your applicator solution ready.

Most retailers that stock window film will also carry the applicator film as well. However, you can also make your own and it will work just fine! Get a small spray bottle and fill it with distilled water (you can substitute tap, but the cleaner the water, the better the results). Then add just a tiny bit of soap to the mix - about half a teaspoon per quart of water. Mix this up and you've got your sudsy application solution. Spray this onto the window glass generously: don't be shy with it!

Take your pre-cut film and remove the backing from it, exposing the back of the film.

Always apply the backed side towards the window, so remember which side you pulled it from. Once you have it stuck to the window with your solution, take your cutter and carefully cut around the edges, removing any excess film to trim to the exact fit of the glass. Take care not to move the film during this step, or you may end up with uneven edges.

It is usually not necessary and probably better to use the frame of the window to guide your cutter/knife.  If you want, you can use a thin piece of plastic or cardboard to press the film down if you need to when trimming at the corners.

Watch those bubbles!!

Once you've trimmed the film to fit, use a squeegee tool or a credit card to remove any air bubbles from underneath the film. It's important to take time on this step, as this will lead to either a great looking window or one that could use a bit of love later on. Push all the air bubbles out from the sides of the film, and don't worry if applicator fluid starts running over the sides-that's normal.

Stubborn bubbles must be dealt with to get the best looking job.  There are two types of bubbles...  air bubbles and water bubbles. Water bubbles can be removed manually, but most small ones will disappear within a few days. Air bubbles on the other hand need to be removed as well and as quickly as possible. If the squeegee does not work, attempt to rewet the film and squeegee to remove the air bubbles. If they still persist, you will need to slowly lift a corner of the film to allow the air to escape and then reapply the lifted area.

The final step... another spray of solution!

With the air bubbles gone, do another spray over the installed  film with your applicator solution. This will make sure that you have a tight bond against the glass. Go over the film one last time with your squeegee tool and then clean up any excess applicator on the film with your lint-free rag. Once the window is dry, you're ready to enjoy your new view!

Want to remove the film later?  It's as easy as pie!

If you ever need to remove the film from the window for any reason, just peel up a corner and give it a quick pull. Since there is no "glue" underneath, you won't have to worry about harming the glass, which is a win-win!

Jay Harris is a sales associate at Home Depot, and a regular contributor to Home Depot's blog, where he provides advice ranging from window treatments to lighting topics.

Return to Window Maintenance, Repair and Design Articles