Thanks 
The last contest I gave preamble of glass cleaning but now I'll be going deeply into it,....
Glass cleaning is one of the vital place because it's shows the standard of the building, gives good impression from a far, increase the duration of the glass and compliments the architectural work, so the purpose is to
To clean and maintain the window and the glass ensuring they are free from finger marks, dust, visible dirt, keep it visible and away from water marks.
*Method of cleaning.*
Proceed to the assigned location with necessary equipment
(liquid detergent, bucket, glass scraper if applicable window applicator ,window squeegee absorbent clothes )
Put on Personal Protective Equipment PPE (Dust mask, disposable gloves ).
1 Prepare cleaning solution according to manufacturer’s instructions.
2 All glue stains need to be removed from the glass before starting glass cleaning by using a window scrapper (If applicable)
3 Clean the glass by applying cleaning solution with an applicator to sides and top of frames, then to edges of pane and in a zig – zag pattern, to the rest of the pane.
4 Squeeze across upper part of the windows, using windows squeegee tilting handle slightly to push was towards bottom of glass. )
With cloth wipe /dry lower moulding.
Finally finish with a straight vertical stroke down each edge of pane and wipe with absorbent cloth after using window squeegee or wiper
Use telescopic pole to reach higher window
Some of the challenges in window /glass cleaning is burglary, here in Nigeria we have this on windows for protection due to low security assurance, another challenges is about how to handle higher windows, but to add a little comic relief (challenge is one of the bus top in Ibadan Nigeria... ) we get there and keep going, smile
From Nigeria, I've chosen a cleaning company like art of cleaning which is https://www.facebook.com/advatann/
Friendly as professional ,I wrote much about them in my previous entryhttps://steemit.com/artofcleaning/@adeayanfe/there-s-a-particular-feeling-of-a-clean-smell-artofcleaning
Picture source from @advatanncleaningmanagement....
This is helpful and a nice contest from
https://steemit.com/artofcleaning/@culgin/content-crowdsourcing-for-art-of-cleaning-part-2-54-steem-worth-of-reward
Follow, upvote and resteem.... .