[H h20]

 After 18 years i`ve just landed myself my first builders clean,not that i have`nt tried i just wasn`t really interested but decided what the hell and went for it gave a quote and got it,now heres the thing most of the windows have cement splashes on them and stickers,the stickers are not a problem i was wondering if there is a spray that will break down the dried on cement before i tried to scrape it off,with past experience of dried on cement on a few house extensions it is possible to scratch the glass even with a new blade in the scraper,it was the site foreman who said the last window cleaner they used ended up scratching the glass and now decided not to use him,so if anyone is an expert with builders cleans can you please ever so kindly give me a few tips,cheers,Gaz

[JohnL]

thats the problem with cement on glass, you cannot gaurantee not to scratch it, and whos to say the builders did not scratch it?

JohnL

[Jake]

Gaz

wet the glass well before using the scraper, keep the glass wet, and you shouldn't have any problems.

                           Regards....Jake

[Jake]

and change the blade reguarly!

                                 Jake

[Ian_Giles]

Well you can use an acid based cleaner...sigh....you know the one!.....for the life of me the blasted name of it escapes me at the moment
You would have to keep it off the frames of course, but the stuff does break down cement.

But you must tell the site foreman that cement on the glass is a potential risk of scratching.
And check over the place carefully for existing scratches, if there is compo on the glass, you can bet your life the glass is already scratched in places.

Failing that you will just haveto wet thoroughly and use a razor scraper carefully.

It doesn't always mean the glass will scratch.

Ian

[Morph]

Not Viakal - it will turn upvc yellow in time, as will most limescale removers, in my experience.
Nightmare time Gaz.
I have done plenty in my time.  I really try to avoid them now.  the thing is, the only thing I found really works is the old trad way.  Loads of soapy water on your applicator, let it really soak the window, do as many as you can get to, go back soak them again, and scrape with fresh blade, soak again, squeegee off.
Slow tedious job.
Trouble really comes because the same chemicals used in processing sand and cement are used in manufacturing glass, so the cement mix can get pitted into the glass, then it is impossible to remove completely.  This has to be clearly explained to whoever is taking over the site.  When I have had to face that situation, which I have a few times, I have got the manager concerned to physically see what I do and view the result, explaining as I go.  They see for themselves it is not your fault or problem.  Then you get the go ahead, and they accept whatever the best results you can produce.
I will only do a build clean now, if I'm going to get the regular contract.  And initial clean has to be at least double.  

[Moderator David@stives]

Gaz

I wet the glass and squeegiee with top  to bottom strokes only.
And scrape in the same manner.

I point this out to the site manager and that way you cannot get accused of scratches all over the place.
Make sure you demonstrate on one window , It saves a lot of hassle afterwards.

Dave

[batterbee]

Hi Gaz

I do roughly 10 builders cleans a month and i use a solvent upvc cleaner from screw fix and a unger trim scrapper to clean cement of the windows.

I spray the window with this cleaner and it actually soaks into the cement and that loosens it, then just lightly scrape it with the unger trim and it always comes of effortlessly.

If you look a little down the treads and look for one from wightsurf titled upvc restorer you will find some links to the cleaners i use from screw fix i highly recommend them both.

Here is a link for the unger trim www.soapnational.co.uk/acatalog/Ettore6.html this scraper is extremely Sharpe
so use it with care, this scraper fixes to a squeegee handle.

Hope this helps a little.

Regards

John

[H h20]

Thanks everyone for all your advise,i will be speaking to the site manager before i start  for him to inspect the windows for marks and scrathes prior to my cleaning,so fingers crossed if it all goes ok i may get more work from them,cheers,Gaz 

[Easyclean Windows]

Crystal clear 550 will move run off,limescale,water marks,de-oxodisation, the lot be carefull use gloves and rinse but will move absolutley anything

http://www.windowcleancentre.co.uk/productdetails.aspx?ProductID=186&SectionID=26