window security film versus plexiglass versus lexan

[jbmdharris]

Can anyone suggest advantages and disadvantages when comparing window security film versus plexiglass versus lexan?

I have a door with "sidelights" where (due to fire safety) I do not want to install a double cylinder deadbolt. So to keep someone from breaking the glass, reaching in and unlocking the door, I need to do something to the sidelights.

I've heard of this stuff called "window security film" but I don't know much about it, where to get it, if I could install it myself, and how it differs from the "tinting film" seen in home improvement stores.

I could cut a piece of plexiglass and screw it on top of the window and then hide the screws with moulding or perhaps a curtain.

I could try to find a window replacement company that would remove the glass and put in something called "Lexan".

Does anyone have any recommendations?

I've also got a set of patio "French doors" with a similar problem. However, in this case, it's not a fire safety issue. A double-cylinder deadbolt would be fine on this door except for the fact that it's pointless since the French doors have a double-pane insulated glass unit instead of individual panes of glass. If someone were going to break the glass to unlock the door, they can simply walk through the hole where the glass used to be and not even mess with the lock. In this case, in addition to the choices above, there is probably also the option of removing the ornamental "muttons" and replacing them with white metal bars made to look like the original "muttons". Does anyone have any recommendations for the French doors?

[XSleeper]

So the sidelights of your doors are not double-pane insulated glass? What I would suggest, if you want those windows burglar proof is that you contact a glass shop. They will be able to give you the proper answer to your question.

To my knowledge, plexiglass is as weak as glass is, and will crack just like glass if struck. It will also flex, whereas glass would not. Plexiglass is not the answer.

I'm not knowledgeable about the plastic films, but I do know that double-pane insulated glass can be ordered WITH the plastic film, which makes the IGU very difficult to break. I also know that LEXAN is also used where "bullet-proof" installations are specified, so that is definately an option, although a *highly* expensive one. As far as your french doors are concerned, I really don't think that adding some sort of muntins would be the answer to a security problem. If you want to make that door more secure, you could replace the IGU's with IGU's that have the plastic film factory installed inside the unit.

I wouldn't go to too much trouble, though, because it only takes a good kick to knock a door in that is not equipped with a deadbolt. The bottom line is that if someone wants to break in, they'll find a way- like all your other windows on the house. Som newer houses today can be broken into with a sharp knife. (cut through the vinyl siding... cut through the foam sheathing... cut through the drywall... you're in.)

The high crime neighborhoods that I've driven through have steel mesh across the windows and door glass. So if you're worried about security, that and a security system would probably be your best bet.

[jbmdharris]

The sidelights of the door are double-pane insulated tempered glass and both doors have a single cylinder deadbolt. The door with the sidelights is a one piece unit where the manufacturer built a door and sidelights in one piece that is then installed into the home. The sidelights aren't anything custom.

To prevent kick-in, I'm trying to figure out how to buy or make metal plates that screw to the door jamb to strengthen the 1" jamb between the door and the sidelights. The longest heavy-duty strikeplate I can find is only about 12" long. I'm not a physics expert, but I don't think those are long enough. If I had a 2x4 stud behind the jamb, I'd have no problem with it because I could put in 3" screws. However, since it's only 1", I feel like I need to distribute the force along a greater distance of the jamb... such as 3 feet. Not to mention that, but the deadbolt is a somewhat non-standard 12" above the door handle and as such, I can't find heavy duty strikeplates with pre-cut holes at this distance.

Bars and mesh over the windows are a bit overkill and ugly and my wife would kill me if I suggested this kind of thing. The only exception to this might be the French doors which now have an IGU with a decorative wood mutton "grid" that pops out for easy cleaning. If we could find metal bars that look like the mutton grid, they could be attached to the door and no one would know the difference just by looking at it. If someone broke the glass, they couldn't get through the bars and I could switch the single-cylinder deadbolt for a double-cylinder deadbolt. (I could also replace the IGU with some kind of security glass as you suggest as well. Then it becomes a cost trade-off.)

Once I address the issues with the doors, I'll move on to windows. There are only about 4 windows in the house that are easily accessible from the ground. Two of which are on the back of the house and would be an easy target for smashing in.

While I sound like I'm obsessing over this, I'm really only trying to do what I would consider "reasonable and prudent" when it comes to security. The goal is to make it so anyone who tries to break in will take more than 5 minutes of trying or will have to get to at least the 10th crowbar blow or door kick before getting in. This is probably enough to make the smash-and-grab kind of thief go to the next house. As it is now, you take a brick to a small window and you are in in 30 seconds. Not much of a deterrant if you ask me.

[Oberon]

jbmd,

How much do you want to spend on this? Depending on your budget, you have a couple of options.

First, window security films look really impressive in the videos that you see at home shows or sometimes on TV. Of course real life performance might be a tad different.

The window film videos show film that has been anchored into the frame of the window being tested. They also don't mention that they are demonstrating on a piece of 3/8" or 1/2" or in some cases 3/4" glass. surprise, the film works great. But what about real world?

In the real world, you are going to install that film up to the edge of your sash (in almost all instances). Your sidelights are built with 1/8" or possibly thinner glass. Imagine when that tempered sidelight glass is broken. All those tiny pieces of broken glass will adhere to the film and you will be able to take the entire broken window out in a nice package leaving a big hole where the sidelight used to be. If that tempered lite breaks, then that film is going to fold up and drop to the floor carrying the glass with it. The film would actually perform better on annealed glass because annealed does not break into tiny pieces like tempered does, but in the case of the sidelights that is a moot point.

Do the films make the glass "stronger"? Nope, not one bit. If the film is anchored in the sash, then you have the additional protection of the film remaining when the glass is gone. But otherwise, no real advantage.
Also, the films scratch easily and are not always easy to remove and replace when you can no longer see thru them because of scratches and other normal wear and tear.

Acrylics (Plexiglas) and polycarbonates (lexan) are both used in security applications. Both are stronger than glass in a conventional sense...meaning both will withstand an impact that will break glass. Polycarbonates are substantially stronger than are acrylics. Both are more expensive than glass and polycarbonates are generally more expensive than acrylics.

Both plastics scratch - acrylics easier than polycarbonates. Unless treated with a UV inhibitor, both plastics will yellow and become brittle with age and exposure to sunlight. Generally, most polycarbonates are treated; acrylics a bit less so than the polycarbonates.
They are less energy efficient than glass and also less resistant to sound penetration than glass, so that you may actually hear more outside noises when using plastics in place of glass in window applications.
And, generally speaking, most people would look at the installation of "plastic" windows rather than glass as a "cheap" fix. This isn't really true, but it is a very real perception by many folks.

Another alternative is to replace the conventional glass with laminated glass. This is probably the most expensive proposition, but probably also the best.

Laminated glass consists of two layers of glass with a plastic interlayer between the glass. Your car windshield is laminated glass.
The advantages of laminated include…

Strength - laminated glass will break, but the nature of the product means that it will stay in the sash and keep the opening closed.

UV protection – laminated glass will block 99% of UV light from passing thru it.

Sound – laminated glass blocks more sound energy than does conventional glass and significantly more than any plastic.

Laminated glass is “glass”, so it has significantly better scratch resistance than any plastic.

Energy performance – laminated glass does not improve on “normal” glass performance, but glass is better than plastic in this area, so you don’t lose there as well.

Laminated glass is used in hurricane impact applications. The testing for approval in the designated impact areas includes an impact from a 9# 2x4 at 34mph.

There are no films and no plastics currently certified to pass that test. There are glass/plastic hybrids, but those are REALLY expensive.

Some impact film folks will say that they are hurricane impact certified - they are lying. Okay, they may not be technically lying, but they are manipulating the system a bit and not being entirely straightforward.

Anyway, laminated glass is absolutely ideal for what you are discussing, but it ain’t cheap.

Overall, the film would be the least effective option, but also the least expensive.

Plastics may look like a good investment, but unless you actually replace the IGU, then you will be attaching the plastic on the inside of the IGU? One other thing to consider in that case is the potential for heat build up…you may void your window warranty and also potentially damage the IGU…but that would depend on a couple of other factors such as how much sun, etc.

Okay, long enough!

[em69]

You can read about one product called Ace Clear protection here:

http://www.usace.com/

[PAP]

You can purchase an install kit from this website if you want to install window security film yourself. The cost is much cheaper if you do - DIY Window Security Film - http://www.diywindowsecurity.com.

[johnam]

Lexan is the only sure thing.

[Hellrazor]

The other thing i didn't see mentioned is.. even lexan is only as strong as the frame that supports it. That nice fancy 1/2-3/4" thick molding is going to survive what?