Cleaning Windows After Construction

Cleaning windows after construction can be a costly experience if you do not understand the properties of the glass. It is never as simple as removing waste of glass with a scraper... I have put together some information outlining some of the properties of glass found in Australia as well as some of my tried and tested techniques... If you follow my techniques and use care, you should never, ever do major damage to glass again...

I have noticed that many window cleaners are reluctant to take on builder's cleans and that nearly everyone I have spoken to have horror stories. This does not have to be the case as there are some simple techniques that take the pain out of things. Listed below are the majority of glass types that we face on a day to day basis and tips to avoid damaging them during cleaning...

Toughened glass (can also be called tempered glass):
One really easy thing is to look in the corners of the glass for the ""toughened"" symbol. In most instances, if you can feel this symbol, it means that that side of the glass can be scraped without leaving scratches as long as you scrape carefully. If you have been using your blade to strip barnacles off a boat, of course the blade will be crap and probably scratch the glass. The same rules apply if you hit the melted dots that sparks from an angle grinder leave when they hit glass. Keep freshening up your blade and try not to use them on the bad side of toughened glass. Concrete etc needs to be scraped with the blade moving in one direction so as to not rub the grit into the glass and scratching the glass (like a sandpaper effect and nothing scratches glass quicker than sandpaper). If the concrete is on the wrong side of the glass, you need to use hydrochloric acid or a 1 inch blade to ""chicken pick"" the concrete off without leaving visible scratches . An! ultra fine steel wool such as 000 can be used but this will leave fine ""spider-web"" like scratches that may just be visible when the light hits it. I am anti steel wool but still use it at times.

As far as I know Moen, GE James and Viridian all make glass with this raised symbol. It will quite often not be present on shower screens and pool fences etc but trust me, these will be toughened glass. To test which side can be scraped, get a small 1 inch scraper with a new blade and test both sides when wet. The ""bad side"" will have a grainy feel and sandy sound whilst the side you scrape will feel smoother. To test this out, try it on a shower screen. There is also one type that behaves differently and it is like the symbols has been melted or branded into the glass this type will scratch on the side where you can feel the symbol.

Toughened glass will generally appear in door ways or windows that could be potentially dangerous if broken.

Laminated glass:
Scrape to your hearts content as you will not scratch laminated glass. When you put a blade on it it will feel smooth. Generally does not have a give away label but during construction may have a sticker that says ""grade a laminated"" etc. Strong like toughened, will be found in most shopfronts but also in houses. Is great to work with.

Float glass: behaves in the same manner as laminated glass but do not confuse with toughened float.

Low e glass: Comfort plus, solar e, solect etc... An oxide coat is attached to laminated glass. This means that the inside will scratch (or mark but I will get to that) just looking at it. The outside can be scraped! A dead giveaway is the drag test. Run your finger on one side and then check the other. Alternatively, wet one side up and run a squeegee on it. You will see the difference straight away. This is great because if you scrape the outside first, you can see what is on the inside which makes things slightly easier as you can't use much on it. Internally no scrapers. steel wool etc can be used as anything metallic will mark the coating. Acetone or glue off (from rapid clean) is fantastic for water based paint, and glue residue. Paint stripper can be used edges where gloss paint has been slopped on to great effect and most importantly, without damaging the glass. This type of glass gets black scratches on it if blades etc are used. These can be removed using Hydrochlo! ric. Low e has a bad rap and can be cleaned quite easily. Despite manufacturers claims, you can use a squeegee... Always be on your toes as sometimes glaziers will glaze these back to front. If you are concerned about being able to tell the difference, there is a tool that you buy that runs a current through the glass. It will light up red when you attach it to the conductive, or low e side of the glass.

I find that the most important thing here is to educate your builders on the properties of the glass. A builder will insist on boots off on a new floor but won't be so careful when it comes to the windows... This needs to change. You should also educate your builder on how busy you are so that they will give you plenty of notice.

Products such as paus protection can be applied and will save everyone headaches in the long run. Paus can bake on an be a problem if left on too long. To remedy this, soak newspapers and attach to the glass with tape. The protect will come off, it just needs to stay wet.

Hope this helps... Feel free to drop me a line if you need any further assistance.