Nathen i've been doing the job for 16 years and have a pretty good idea of how things are done.
Just read back over smurfs posts and see what he says, "i just spray hypo and wash it down with a hose pipe if i cant be arsed to get the pressure washer out", As an example of one ! How many times have you been able to do that ? me never !
i just dont understand why he says this stuff.
On one of my posts i think on the "what have you washed" or certainly on my web site, 1nkservices.co.uk in the gallery. I show a before and after of some grey slabs. Obviously after brushing down with a sweeping brush, all i did was brush on my hypo mix and left it (not to dry, so topped it up) whilst i did the block pathing by its side. Then after 15/20mins or so, i simply rinsed it down (the slabs) and they came up great.
What ratio are you mixing ur hypo or what concentrate do u use?