goofy question about thermal stress breaks

[EWF]

X2 what Howard says.

 

If you are in the business long enough you will get some breakage - and not always where you might expect it.  Remember one home with fairly small double hung windows where we installed a 50% Neutral film and had about 5 out of 28 windows break.  Glass must've been especially cheap stuff or poorly installed.  And a store with huge plate glass (not tempered) splicer windows - there was is even shading from an overhang - that a GC insisted we install blackout to, even though I recommended against it and told him there would be no warranty if any broke.  Not one did.

 

In a typical year I get just a few reported breaks. Even taking into account that not all breaks get reported that's not much.  But I will always warn people if they have windows that would be expensive to replace.

 

Hi Suntint,

 

I agree with you.

 

At times, there is seemingly no rhyme or reason to this phenomenon.  Windows that should theoretically not be in the high risk category break while those that are clearly exceeding the guidelines endure.

 

EWF has paid glass breakage claims on 2M Clear Film.

 

Obviously, the quality of the glazing materials and/or workmanship is an issue.  But it is an argument you will never win with a customer and as such, you should not even attempt to do so.  You installed the film on Monday - on Tuesday the window was cracked.  In their eyes, it's your fault. 

 

-Howard

[Glass Tinting Supplies]

Older glass that has seen as strong wind or 2 is ripe for thermal stress breakage. Also, if the glass has polished edges, it can make all the difference. A small chip or burr on the edge of the glass will likely be where the crack will start from. Often very hard to know if the edges are good or bad.

Cheers

[Tintguy1980]

And thermal breaks always begin precisely perpendicular from the edge before meandering off like a snake. The number of branches the crack takes is indicative of glass quality. I want to say the higher number of branches, the better the quality (or is it vice versa?).

 

Also, thermal cracks only occur within the inner thirds of an edge; never in a corner (or the 1/6th of an edge that forms a corner area on either side of the inner two thirds .