Window Film Blog
A photo of a woman installing window film for a post on how to Install Window Film

How to Install Window Film Easily Yourself

Window film is a cost-effective way to upgrade your windows to make your home more comfortable. It can help with things like solar control (a room that is too hot), glare, furniture or wood floor fading, UV protection, energy efficiency (think lower AC bills), and added daytime privacy.  Sounds amazing, but…how to install window film? With the right professional grade film and a bit of preparation, installation is easily something you can do on a weekend!

TL;DR: check out our installation video or download our printable instruction guide!

What is window film?

Before we talk about how to install window film, let’s discuss what it is.

Window film – sometimes called window tint – is a high-technology product made to enhance glass performance. Window film is constructed from Polyethylene Terephthalate (PET) a common type of polyester used widely in clothing, packaging materials, and other films including video, photographic, and x-ray. The polyester is treated with a component (dye, metal, pigment, or ceramic) and applied to the inside of a window to selectively filter the UV, infrared, and visible wavelengths that enter a building (or automobile).

The performance of window film is rated by the National Fenestration Rating Council, a non-profit agency that rates the performance of both windows and window film. This is a voluntary rating and testing protocol that you should look for with any film you purchase. Our performance ratings can be found here.

How does window film work?

The component materials (in our case: nano ceramic particles) reflect and absorb solar energy that hits a window preventing it from entering the home. The diagrams below compare how the sun’s energy interacts with clear glass (lefthand illustration) to glass with Concord Window Film’s ComforTech™ 35 Ceramic Series film (righthand illustration) and shows how window film works to control the sun’s heat.

How Does Window Film Work -

How to Install Window Film

Now that you know what window film is and how it works, let’s go through how to install window film like a pro!

How to Install Window Film Step #1: Prepare for the Project

Making window film installation solution

The key to any good DIY project is your prep! The first step for how to install window film will be to gather the tools you’ll need to get the job done:

Common Household Items

  • Scissors
  • Paper Towels
  • Cellophane Tape
  • Towels or Drop Cloths

Window Film Installation Tools (all of these are included in our Installation Tool Kit)

  • Rubber squeegee
  • Razor blade scraper
  • Utility knife
  • Yellow film pencil
  • Spray bottle
  • Slip-Tack solution

Once you’ve got all of your supplies togather, clear off and clean a table or counter to lay out your film. Window film has a liner on it and once you remove it, the film can attract dust and dirt, so you want your space to be as clean as possible. Dusting and vacuuming the area where you are going to work before you begin.

Next, prepare the installation solution. The solution is needed to activate the dry adhesive on your new ComforTech™ film, is used to clean your windows in preparation for your film, and helps keep everything gliding easily as you install. To make the solution, fill the spray bottle with water up to the FILL RING line. Then put 1 teaspoon (tsp) – about twenty drops – of the Slip-Tack mounting solution into the bottle, replace the top, and gently shake until mixed. The approximate mixture would be one teaspoon to a quart of water, but you do not have to be exact. You can also substitute baby shampoo for Slip-Tack.

How to Install Window Film Step #2: Clean Your Windows

Clean your windows to prepare for window film

The next step is to prepare the window for film by cleaning it. Start by spraying the window with the installation solution and then scraping the glass clean using the razor blade scraper.  Take care not to cut yourself while using the razor blade scraper.

After all the dirt has been removed with the razor, wet the window again. Using overlapping strokes squeegee the entire window being sure to wipe the squeegee clean with a paper towel between strokes to remove any accumulated dirt. 

Finally, wipe the edges of the glass dry with a clean paper towel. Most of the dirt and contamination that makes its way under window film comes from the edges of the glass, try to get them as clean as possible.

PRO TIP: It’s helpful if the outside of the window is also cleaned so you can see whether the inside is ready for film.

How to Install Window Film Step #3: Measure & Trim Window Film to Size

Trim Window Film to Size

If you’ve purchased one of our window film kits (double hung, casement, storm door, patio door):

Unroll your film pieces onto your clean, flat surface. Take one piece of film and place it on one window sash covering the glass with at least a 1” overlap on the top and left edges of the sash.

Now, holding the film in place, mark the right and bottom edges of the film with the yellow film pencil about 1” beyond the glass edge for trimming.

Back on your prepared clean, flat surface, use the box as a straight edge to draw lines with the yellow marker to mark your cut lines. The marked film size should provide you with a piece of film that has a 1” overlapping border to the glass edge on each of the four sides.

With a pair of scissors, cut the film to size along the cut lines.

If you’ve purchased a roll of film:

If you’ve purchased a roll of film, then measure just the glass on your windows. (You likely already did this before you ordered film, but measuring twice is not a bad idea :)). Add 1″ to each measurement for the final trim at the window. So, for example, if the glass measured 26″ wide and 31″ high, you would use these measurements to cut your film: 27″ wide and 32″ wide.

Place the roll of film on the counter and pull out a length of film. Measure out the film using a tape measure and then use the yellow film pencil to mark where you want to cut the film. You can use the shipping box as a straight edge to mark your line. Do the same for the other dimension and then with a pair of scissors, cut the film to size along the cut lines.

If you’ve purchased custom cut film:

These pieces of film should be cut to the size of your windows already and won’t need any trimming before the next step.

How to Install Window Film Step #4: Wet the Glass

Wetting the glass for window film installation

Now you will fully wet the glass before placing the film on it.

First, open the window slightly and place a towel underneath the sash, covering the sill. Close the window on the towel, securing it in place. This will protect your wood trim and sill from any water damage. Place another towel on the floor below the window to catch any additional liquid.

Then spray the glass completely with the solution being careful not to leave any dry spots.  Center the spray on the window while avoiding spraying near or into the edges of the window.

PRO TIP: Wet the window thoroughly, but do not spray any water directly on any of the outer edges. You do not want to flush out any dirt or grit which may still be embedded under the frame of the window.

How to Install Window Film Step #5: Remove the Liner

Removing window film liner

You are almost ready to get the film on the glass, but first, you need to remove the film’s liner.

Every piece of ComforTech™ window film has a clear polypropylene liner protecting the film’s dry adhesive. To set the film up for installation, the liner needs to be removed. A set of tabs are attached to the film to allow you to separate the film from the liner.  To remove the liner, pull the tab labeled “PEEL HERE” (this is the liner side of the film) and begin the separation of the liner from the film. 

PRO TIP: If your film does not come with peel tabs, you can use two pieces of cellophane tape to remove the liner. Simply place two pieces of tape on a corner of the film – one on the liner side of the film and one on the film side. The tape should overlap slightly. Pull the pieces of tape apart to remove the liner. 

Once the liner begins to separate from the film, place the film on the wet window with the liner side out.  The film side should temporarily adhere to the wet window.  While holding the film in place on the window, remove the remaining liner while spraying the installation solution on the exposed adhesive side of the film.  Once you remove the entire liner, please make sure the entire adhesive side of the film is thoroughly wetted with the installation solution.  

PRO TIP: This step is easier if you have another person to help you. They can help hold the film as you pull the liner away and spray the film.

How to Install Window Film Step #6: Apply Film

Applying window film to window

Once the adhesive side of the film is thoroughly saturated (remember the liquid is needed to activate the film’s dry adhesive), you will flip the film so that the adhesive side is facing the glass.  As a reminder, the non-adhesive side of the film will be the one with the tab still attached.

To do this, carefully pick up the left edge of the film with your right hand and remove the film while using your left hand to grasp the other side of the film. Then flip the film so that the adhesive side is now facing the glass.

Make sure that you apply a generous amount of installation solution to ensure that film slides easily on the glass. 

Place the adhesive side onto the glass and allow the film to slide onto the windowpane. There should be enough slip so that the film slides around easily. Center the film on the glass with the 1″ overlapping edges on all four sides.

PRO TIP: To avoid transferring oil from your hands onto the exposed film, give your hands a light spray with the installation solution prior to handling the exposed film.

How to Install Window Film Step #7: Smooth in Place

Smooth window film in place

Now that the film is in position, completely wet the outside of the film with the solution again.

To set film, begin squeegeeing the film by making a “T”.  Start by making a horizontal stroke across the top edge 2” below the glass and then a vertical stroke down the center of the film stopping 2” from the bottom glass edge. Be sure to push the squeegee across the film; do not pull it.

After creating the “T” go back to the top and continue squeegeeing the film using horizontal strokes that start from the center and go to the left and then right.  Continue to be careful not to squeegee to the edge of the film, leaving a two-inch border.

PRO TIP: DO NOT SQUEEGEE TO THE EDGE OF THE FILM. If you squeegee all the way to the edge before trimming, you risk causing dirt and grit to get sucked back under the film. Squeegee the entire window, but leave a two-inch border around all edges.

How to Install Window Film Step #8: Trim Film Edges

Trimming window film to size

With the film set in place, we will now trim the excess film edges on all four sides.

Take the squeegee and now push the film to the edges of the window frame. Then, starting in the top left corner, using the covered scraper as a guide, place the utility knife between the covered scraper and the window frame and begin trimming away the excess film as close to the window frame as possible. Trim the remaining three sides with the same technique.

Once the film is trimmed, carefully pull off the excess. Make sure that as you remove the excess, you are pulling it away from the window edge. Do this carefully so you do not rip the film on the glass. If there is still excess film at the edge of the frame, carefully use the knife to trim it. Respray the outside of the film and squeegee again.

You may notice there is water still under the edge of the film. You will squeegee this water out after the film is completely trimmed.

PRO TIP: Take your time trimming the film. Make sure the film is pushed all the way to the edge of your frame with the squeegee, and place the knife as close to the frame as possible.

How to Install Window Film Step #9: Squeegee Dry

Squeegeeing window film dry

You’re almost there – last step! Now you will squeegee all the way to the edge to seal the film.

If the squeegee does not glide easily over the film, spray the outside of the film with more installation solution to lubricate the motion of the squeegee. As before, use pushing strokes from the center of the glass to the edge, moving from top to bottom.

Next, thoroughly re-wet the film and squeegee the entire film again with push movements. Apply enough pressure to ensure you remove any excess water between the film and the glass.  Be sure to apply enough solution so the squeegee glides easily.

The last important step is to dry the edges of the film. Wrap the squeegee in a folded paper towel and starting 5-6” from the edge, squeegee toward the edge. Any remaining water left under the film should be pushed out at the edge and absorbed by the paper towel.  Repeat if necessary to dry the edges. Once dry, installation is complete.

You may notice some small water bubbles under the film, this is normal, and they will disappear as the water has time to evaporate.

TWo windows with window film installed

Congratulations! You just installed window film!

ComforTech™ Series film can take up to 30 days to fully cure, small water bubbles are common during the drying process, and these will evaporate.

Please refrain from cleaning your windows for the first 30 days. After that, you can clean your windows as you normally would with a soft, non-abrasive cloth and mild cleaning agent.

Now sit back and enjoy the comfort of Concord ComforTech™ Ceramic Series Window Film for years to come!

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