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Window film vs laminated glass

billybob111's picture

Someone punched a hole in a window and broke into my house.  I need to replace the broken glass.  I'd like to use laminated glass or apply a film to regular glass.  The sash is wood and about 100 years old.  Will laminated glass fit or is it to thick?  Also,  I'd like to strengthen my other windows.  If I apply film to the windows and someone tried to break them, wouldn't the film keep the glass together, but allow the glass to be punched out of the sash as the film isn't set beneath the glazing?  Wouldn't the window would break along the line where the film and glazing meet?





billy (post #207291, reply #1 of 5)

Tough to answer-

Tempered glass, that breaks in a zillion tiny pcs. is meant to limit harm to human flesh.

Safety glass is the non tempered way to also do the same thing.  I'm not sure if auto safety glass film is thicker/stronger than residential, but it certainly often stays together.  It's the sharpness of the glass that could cut the film.  However, the mess of the damage should be retarded.

Laminated is by definition-two pcs of glass-safety adds the film between the layers.  Your sash/stops/glazing would have to accomodate the added thickness.  Would the glass break and fall out at the glazing/sash line with after market film applied to the surface after glazing?  Beats me, but I suppose it could, with the bottom edge of the glass trapped (for the most part) I think it would show cracks, but wouldn't easily fall out.   Most busted out glass opens up the area beyond the edge of the sash, leaving those schards that hopefully cut the intruder.

Doors with glass and windows within 3' (I believe) of doors,  windows over (6'?) tall, windows within 18" of the floor, and windows/doors within 32" of the outter edge of tub/shower or within tub shower area...........and the shower doors, all have to be safety or tempered glass.

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If this is a few window panes (post #207291, reply #2 of 5)

If this is a few window panes that you want to make burgler-resistant, I'd replace the glass with Lexan or some such.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Compared to glass, how easy (post #207291, reply #3 of 5)

Compared to glass, how easy does Lexan scratch?

Easier than glass, of course, (post #207291, reply #4 of 5)

Easier than glass, of course, but fairly scratch-resistant.  And you can purchase it (for more $$) with a scratch-resistant coating.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

"Tempered glass" and "safety (post #207291, reply #5 of 5)

"Tempered glass" and "safety glass" are both 'ordnary' glass that has been heat treated. "Laminated" glass is made of multiple layers of glass with a plastic film between layers.

The films are for different reasons. Some are there to provide a tint, or reflection. Others are there for strength. The windshields of American cars have an exceptionally thick, rubbery plastic in them, that holds everything together.

3M makes a variety of films for applicatin to existing glass. Some of these films are intended for 'security' purposes; 3M has a film of one such window being attacked with a sledge hammer.

An old-style wood window can take glass of nearly any thickness. You might have to trim the molding, though.

Lexan and plexiglass are two different plastics used as replacements for glass. Both will scratch and 'haze over' much quicker than glass.

Lexan is more scratch resistant than plexiglass, and is much stronger when new. However, Lexan will lose a lot of it's strength when exposed to sunlight.

Neither of the plastics will be recognized by 'glass break' detectors in alarm systems.

That's that the OP really needs; a monitored alarm system. Nothing like having men with guns respond when someone breaks a window.

What about window bars? Well, first check your homeowners' policy. Insurance companies don't like 'burglar bars' in housing, because of fears that the same bars will trap someone in a fire, and imterfere with firefighting activities. If you go for the bars, have them mounted so they can be easily removed from within. There's even a UL standard for such designs: only one action, such as stepping on a foot pedal, is allowed to release the bars.