[Blast Away]

You'd be wasting it on block paving mate applying before.

We clean block paving just by pressure then apply after should we think it needs it for any heavy places.

Same with Indian sandstone. Take off what you can with pressure then no doubt lichen blackspots will be visible or tough staining from overhanging trees like in this video below where we clean and rinsed all with just pressure revealing the stains. Then brushed on hypo strong and left it.

http://www.youtube.com/watch?v=nxhaW3wu2iM

[mickwc]

we use lots of hypo, same as blastaway, put down after fisrt clean, wicked stuff!!  make sure you cover all your clothes tho, or like us you will be walking round with white splash marks everywhere. i'v tryed spraying it but have found watering can best method, for drives and patios

[Cliff perkins]

Cheers all seems best method is to clean 1st then see where you need to apply after,
Will try this method out on my next clean.

Thanks every1

Any1 else feel free to put some more advice up if you have some.