There are many problems with WFP thats why customers drop guys because of runs ,spots and glass being left wet also ledges can not be cleaned properly either, anyone who says they can are dreaming because you can't clean anything properly unless you can see it. With trad you can see the end result and I personally wont leave a job till it's right.
Regards
Adam
I clean upstairs sills all the time...isn't a problem at all.
Did a clean for an estate agent earlier this week, a one of house rental clean (I do quite a few of them) and the sills were specifically requested to be cleaned as they were covered in green algae.
Cleaned the inside of the windows too, sills on the outside?
??
Spotless
I don't use a sill brush, I just use a superlite brush (and they are not the best for one off cleans on very dirty windows) and change the angle a little on the cheap plastic angle adapter to be sure I can get at the sills properly and away I go.
As for working in the rain, yeah, it can be done fine, but you are going to have problems working if there is driving wind in heavy rain.
Some places you will get away with it, others you won't.
And if you are trad then you can forget Georgian and leaded work in the rain, I know you can use a cut down squeegee and a small applicator on Georgian work, but it won't be a good job.
You just have to assess each job as you go along.
Ian