I purchased and installed a set of sliding mirror doors 2 weeks ago. In the space of two weeks all four of the doors have developed cracks in them. A couple of them are at least a foot long.

I have not been abusing them excessively. The one crack I was aware of causing was when I did open a door a little bit too hard and it caused it to knock into the adjacent door. Surely the doors should be built to withstand a little bit of a knock.

I can think of two possibilities - either I have installed thew in such an incorrect way that means they are incredibly fragile, or the doors are of very poor build quality. I did follow the instructions to the letter.

Before ranting at the manufacturer - is it possible that I have just missed something obvious when installing that could have caused them to crack so easily?


I forgot to add a conclusion. I contacted the manufacturers and they said they had never seen their doors crack so easily before. Without any argument they replaced the doors straight away. The replacements are still going strong without a crack > 6 months later.

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    I would think anything you may have missed which could be damaging the door, would also make it difficult to operate. Like, if it was installed at an angle and under stress. Are these just sliding closet mirror doors? I abuse the heck out of mine. Kids throw things at them. They get slammed. 8 years, they haven't cracked. Just a couple of small chips from projectile toys. :) – maplemale Jun 1 '15 at 19:26
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    Were rubber bumpers provided that weren't used? – isherwood Jan 29 '16 at 14:34
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    No bumpers were provided. – Mongus Pong Feb 1 '16 at 10:23
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    I can't seem to find the close reason for, Well, ^^ there's your problem right there.... – Mazura Oct 31 '16 at 7:05
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    I’m voting to close this question because it's been abandoned. – FreeMan Jan 2 at 19:59

The main problem is that the energy that is stored when you open and close the doors are delivered direct to the mirror and the frames, cracking the glass or the wood. Check to see if your installation was done properly. Also, if you don't want to go through problems with the manufacturer, you can try to do some wood work and reforce the frames. Try not to hit the sliding dors when opending and closing them.

Hope it helps!


There are things people have missed telling you about that can damage a mirror. Such as rapid temperature changes which will crack or even break most glass.

Is the glass near a heating vent? Is it near a window? Is there outside air infiltration/drafts? Is it in full sunlight? Things leaned against the mirror hot or cold?

Also sound can crack glass. Things like stereos, TV's, etc. if too loud or too close to glass could be a problem. Also sound you can't hear such as ultrasonic bug repellers, ultrasonic dog training devices, aircraft noise(Both sonic and ultrasonic here.), minor earth quakes(Subsonic vibrations), etc.

And in theory you could even see electromagnetic/electrostatic/piezoelectric effects from high voltage power lines, induction cooking devices, damaged microwave ovens, radar, etc. which could damage a mirror because of the metallic coating on it.

Anyway there are lots of other ways to damage a mirror besides just breakage, or torsional stress. You should check for other things in and around your home to make sure you don't end up with another broken mirror.


If the doors are not installed in a plumb position, ie have a twist to them with one side plumb and the other side not plumb, this may cause a tension on the glass. That coupled with the shock of hitting the wall may cause a crack. Sounds like you've one nice door hardware company that replaces stuff at the drop of a hat. Or, could this be an admission of guilt? "It happens all the time. Here's another customer with that same problem. Let's replace." Cheapest product is not always the best. Pay more, get more.

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    Will it's been > 2 years now and the replacement doors are still going strong. It does suggest it was the doors and not the installation that was at fault.. – Mongus Pong Oct 20 '17 at 8:08

The problem is that the frames of those things are not rigid enough. Basically for the door not to crack, one of two things has to be true: either the frame has to be built stronger than the iron gate of Dr. Evil's volcano lair, or the track has to be perfectly level and rigid. In your case, probably neither one of those things is true. You probably have some cheapo plywood subfloor that undulates like Miley Cyrus. Short of cutting out a 4" strip of the subfloor and replacing it with half-inch plate of hot rolled steel, you are unlikely to get a proper surface for installing quasi-crystalline doors.

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    So you're saying that all sliding mirrored doors that are installed should crack, unless the subfloor is replaced with steel plate? – Tester101 Jun 2 '15 at 15:02

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