Mirrors spontaneously cracking

[derje]

Hi there...I've been searching the net and hoping someone can provide some insight.

I live in Toronto Canada in a high rise condo. I have several mirrors in my unit: some are hanging from the wall (they are approx 20 lbs); one is leaning against the wall (6 ft high x 4 ft wide); one is a sliding door to a closet (full mirror); one is a piece of furniture (a night table covered with mirrors).

I';ve had this condo since 2005. The closet mirror being there since it was built, and all other mirrors since 2009.

Last month after a thunder and lightning storm I noticed 3 of my mirrors all had cracks in the them on the corners. All the affected mirrors are also beveled.

Two days ago after returning from a week away, I noticed a forth mirror cracking. There was a lightning storm while I was on the airplane that lite up the sky.

Today I found the closet mirror (completely flat) that slides side to side - cracked on the corner as well!

My condo unit is next to a single elevator. I live across the street from a hydro station (sometimes when a transformer blows the unit shakes).

The mirrors cracked all recently and I am trying to figure out why all of a sudden this is happening and how I can prevent further damage.

Could it be due to the lightning storms?

 

[apape]

I have a 4 x 3 beveled 20lb mirror hanging on my wall. Two days after hanging it there was a couple major cracks in the lower right corner. My 14 year old and 12 year old swear they didn't do it. I really don't care if they did I just to know if this thing is safe. Despite their repeated denial I have to assume they accidentally did it.

 

[fresh_42]

They might be innocent after all because you cannot know whether the mirror had internal tensions which broke accidentally. If you want to be sure that it is safe, then you put a self-gluing transparent film on its surface, such that single parts cannot fall apart.

 

[Keith_McClary]

cracks in the them on the corners

You mean a triangular piece broke off the corner?

 

[Tom.G]

It sounds as if they were either mounted on an uneven surface, or framed in a frame that warped, resulting in some internal stress.

A loud thunder clap from a nearby lightning strike could have induced enough vibration in either the mirrors themselves or the surface they were mounted on to crack them, especially if there was some acoustical resonance. (plausible, but I don't know how probable )

Cheers,
Tom

 

[jack action]

A loud thunder clap from a nearby lightning strike could have induced enough vibration in either the mirrors themselves or the surface they were mounted on to crack them, especially if there was some acoustical resonance. (plausible, but I don't know how probable )

I lived in an old house with the original wood windows and the original glass made with the Fourcault process (that is, they have waves that distort the image seen through the glass), and they do vibrate - to the point of making very loud noises - when there is a loud thunderclap. But never they have cracked because of it.

 

[DaveC426913]

I live in Toronto Canada in a high rise condo.

How high up do yo live? What floor?
Are the mirrors secured at the corners?
How rigidly-secured are they?

I am eyeing the swaying of the building in strong winds. If the mirrors are strongly secured, perhaps the distortions in the walls are twisting the mirrors.

(Although I'd expect you'd see cracks in the drywall first.)

I think I'd go with thunder claps afterall.

 

[teddeski]

move. it's a sign. bad mojo.

 

[rogeragrimes]

One plausible theory: All the mirrors have microcracks in them already, but you can't see them...and the thunderstorms are creating pressure differentials that cause those microcracks to become visible cracks. Why are they suddenly happening? One, either they have been happening, but you weren't looking for them, and so you missed them, especially when they were smaller. Or the temperatures or temperature changes in your place finally "cooked" the mirrors so that they are now permanently more brittle than they were and subject to pressure changes which reveal the microcracks?