[TVCS]

Hi , did a pressure washing job today, mostly concrete paths and flag stones.  Got asked for a price for a large area of block paves too.  Gave price and all set to go ahead when the weather pics up later in the year. 

 Now, I have done plenty of block pave cleans before and they all came up like new but this is the worst case of lichen I have ever seen.
 I know for a fact that there will still be some black spots left after I have gone over the blocks.  I dont really want to blast them with a turbo lance and was wondering if there is anything on the market that can be applied before hand to start to break it down a little before I go in with the old pressure washer. 

Thanks in advance for any replies.
ANT
TVCS

[trevor perry]

you can apply algon with a watering can a couple of days before you do the job this helps,

[steve doyle]

Little and often seems to be the best way,

http://www.pavingexpert.com/maintain_02.htm#acid

quite a usefull gathering of information,