How to install window safety film

Broken glass contained by window safety film.

Safety window film is a wonderful product to add an extra level of safety to your windows. This product does not prevent windows from breaking but post-break, contains broken glass shards so that little fingers can’t get access to them. 

If you didn’t read my previous post on how to baby proof your windows, my little guy broke our old door windows and almost had the worst accident. I’m just saying, with a wayward toy, this stuff happens.

This tutorial is a step-by-step guide on how to install safety film for your home windows.

But, I’m not going to lie, when I installed this stuff I had no idea all the gear that was required to properly do the job. 

Like who knew that using tap water in a wetting solution could destroy the film? Wait, what’s wetting solution?  Oh boy… Fear not, it’s seriously not that bad, you just need a bit of product prep.

Tools & supplies you will need:

  • Safety window film
  • Measuring tape
  • Spray bottle
  • Distilled water
  • Tear-free baby shampoo (check!)
  • Paper towels
  • Clear tape
  • Razor knife or box cutter
  • Sharp scissors
  • Heavy duty scraper 
  • Hard edge squeegee or window wiper
  • Permanent marker

I used a 4 mil thick safety film that is a 30 inches x 10 ft. from a generic brand I got off of Amazon. It was about $20 which I think is a great price for the amount of coverage and peace of mind you get. Of course this product does not substitute watching your kid but it’s a nice preventative layer.

Make sure you read the product specs before you purchase. For example, this product is not advised to be used with windows over 40 years old or with panes made of plastic or acrylic. Also, they make up to 60” wide sheets for you big-window folks out there.

SUPER HEADS UP: You do NOT want to do this with your kiddo(s) around. Save this install for after bedtime or the illustrious 3 hour nap sesh (le sigh, don’t we all wish).  I was able to install all by myself but many people prefer two people to do the job for larger windows.

Of course follow the manufacturer directions as they may vary from what you see in this how to. Ping me with any specific questions:  I’m happy to help!

How long did this take?

  • 1st pane of glass = 10 min (this included prep)
  • All other panes = <5 min

Step #1: Make your wetting solution.

Spray bottle, diluted water and tear-free baby shampoo

The wetting solution is used for two important functions:

  1. To clean & prep your window
  2. To help with positioning and applying the film to the window

The water will eventually evaporate leaving a perfect fit of the film to the window. This drying process can shockingly take up to a month so don’t freak if you see small bubbles or the film becomes a bit hazy at first as they will go away after the film fully “cures”.

Please note, don’t use tap water because it may have hard elements that can destroy the film. Use distilled water. We only drink tap in our home so this was a bit annoying to go buy distilled water. 

  • Use 1 drop tear-free baby shampoo per 4 ounces of distilled water.

Step #2: Prep and clean window.

  • Use spray bottle and apply wetting solution to glass.   
  • Use the hard edge scraper (I used a putty knife and some folks recommend the edge of a credit card) to remove any remnants of dirt, old paint/silicone, boogers, or unidentifiable baby schmutz.  This is super important because any schmutz will create a little halo spot on the film after it is applied and this will drive you crazy.
  • Wipe down edges of glass pane with paper towel
  • Make sure there isn’t any residue or schmutz.
  • Pause and think to yourself, “Ah, that’s what a clean window looks like!” (Or, am I projecting?)

Step #3: Measure twice, cut once

Use permanent marker to trace your cut lines on the safety film.
  • You will need to pre-cut the film before applying to the window so first measure the window pane size.
  • Allow an extra 1/8” gap on all sides – I promise you as you get through the roll your cut lines will compound any measurement flubs. Swearzies, you need a buffer.
  • Lay film flat, release liner facing up, on a clean surface.
  • Use the marker and measuring tape to lay-out the cut lines. Don’t worry, the sharpie is on the release liner side and will peel off. I made a heavy dotted line to help with my cutting.
  • Cut with scissors to spec.

Step #4: Remove the install liner

  • The install liner film is clear and sooooo thin that at first I thought the product came without it. So I hope you got your eye exam this year!
  • The film can stick to itself easily.  Use the clear tape to anchor down the top side underside of the film.  I just made 3 little inverted loops, attached along the top. 
  • Slowly pull off liner, pausing every 3 inches to wet down the exposed film.
  • Do not leave any dry spots and I just did an extra spritz at the very end for good measure. 

Step #5: Apply safety film to the window

xacto blade touch up to trim excess safety film on window
  • It’s show time – get that film onto your window (you may need two people for larger pieces)
  • With enough wetting solution, the film should be able to be positioned slightly (like 1/8") but don't expect to move it around a lot.
  • Expect there to be overlap of film to the window edge as it needs to be trimmed with the blade.

Step #6: De-Bubble Mania

  • It will get super-bubbletastic so use the squeegee to push out the bubbles - honestly, I think using my fingers was the best way to de-bubble but see what you like.
  • Assume you will need to do a few rounds of debubbling - it took me 3 rounds. 
  • As you squeegee out the bubbles, a little bit of water will collect at the pane edges so take breaks to wipe up with paper towels.
  • Remember – your window film may develop bubbles over the drying process which can take up to 30 days. If they are super small, they should naturally disappear when the film is fully dry.

POST INSTALL: Maintenance & cleaning

  • Never clean with any abrasive solvents or cleaning tools that may scratch the film.
  • Mild, standard ammonia based window cleaners and a soft towel or squeegee should do the trick.

Did you find this tutorial helpful? Awesomesauce. Please “like” below and don’t forget to let me know how the install went in the comments below.