[Andrew Bishop]

Have any of you had problems doing builders cleans, using a scraper, when the glass is rough to the touch and ends up scratched all over? It may not be your fault........

We had a large luxury house to clean inside and out for the builder on the last day before the new buyer moved in. The windows were covered with all the usual plaster, cement, labels, etc, and the metal scaper was essential; the job could not be done without it. Anyway a week later we got a letter stating that we had scratched the glass and we would have to pay for replacement. Went round to have a look and yes they were terrible, scratches all over; at first we denied that we could have done this because we use scrapers every day and do not have any problems with scratches.

Anyway having done a lot of research on glass manufacturing we have established that the cause of this was a manufacturing defect; poor quality control in the toughening furnace, producing glass with a fragile surface covered with glass fines just waiting for the window cleaner.

This could apply to you if;

1. The glass is rough to the scraper. It might make a tinkly noise.

2. This fault affects only tempered/toughened glass. Look for a kite mark and the name of the toughener.

3. It affects only one side of the glass, but made up into a sealed unit could affect both sides of the unit. Usually it would be on the opposite side to the tempering stamp.

4. The scratches are all over the glass, not just a few isolated ones.

DO NOT EXPECT THE GLAZIER TO HELP YOU OUT ON THIS ONE!

The actual cause is glass debris left in the furnace which has got onto the rollers which transport the glass; this debris is then tacked onto the glass sheet, bottom side only as it passes through the oven. When the window cleaner comes with the scraper, minute fragments of glass are broken off and moved across the surface thus causing the scratches. It looks as though it was the cleaners fault and as everybody else pleads ignorant you will get blamed.

For the full story see Dan Fields website www.stopscratchedglass.com/challenge/glass_quality.asp or www.scratched-glass.net also look at glassfiles.com discussions search for scratched glass

This has been a big issue in USA and all UK window cleaners ought to be aware of the problem.

I would be interested to know how many others have had a similar experience?

[windows_chepstow]

Andrew,

I've not experienced this problem, but grateful for being made aware of it.  Also, your thread was excellently explained.

Thanks, but can I ask a couple of questions?

Was it not obvious the windows were being scratched as you cleaned?

Also.

What was the final outcome?  Did you cough up?  Would your insurance cover it (once you paid the excess).  Personally I'd provide all the information I could to try and show the customer where the fault lay.  If they still were adamant it was my fault - I'd advise them to take legal action against me.

It seems blatantly obvious the fault is not with you.  We use scrapers day in, day out and they don't mark the glass.

[Jonathan Adams]

Hi Andrew

Yes we have had the same problem, as you say its on tempered glass, we find usually on the architectural type. The sad fact is that if the builders/glaziers covered the window with some type of protection and all we had to do was remove tape etc there would be no problem, but i have yet too come across a builder who has done this.

Regards
Jonathan

[replacement]

Yes, read about this ages ago here http://www.stopscratchedglass.com/about/

Now before i do builders clean i explain about this and i get them to sign a wavier if there is any scrathced glass, all have been fine signing it as well and makes me not liable if there is a scrath after i finnsih. If they dont want to sign i will not clean them.

Justin

[bill_sykes]

I have found that dry scraping glass ,especially mortar 

tends to scratch  because of the grit being just as

hard as the glass.Lubricating the the glass with a

soapy applicator helps prevent this.

[karlosdaze]

When ever doing shop doors, they are usually always tempered. Test a small patch in an inconspicuous place first (i.e.bottom right corner). If you get the dreaded scratching sound, don't proceed. Even a soaked applicater will scratch the surface, pulling the fines with it.
Leave them, tell the builder the problem, get him to sign a sheet saying you refuse to clean them. You learn from experience. He will usually get a site cleaner to scratch them up just fine!

[Pureandclean]

Just sending out a letter to domestic customer at moment, claims landing window scratched.
21 years had 2 customers complain about scratched glass, other one turned out to be on the inside.
I have downloaded information from the scratchedglass web-site to froward on to customer. Web-site explains that tempered glass is generally fitted in landing windows, will see what kind of response this brings.

 : Blessings  :

Graeme

[Derek_Walker]

When we used to do builders cleans many years ago, the main culprits for scratching the glass were the painters. they would just sandpaper all the edges including the glass ready for painting. Mind you they were not predudiced they would also paint the carpets, bathroom suite, kitchen surfaces, in fact anything that did'nt move Ah the good old days.