i powerwashed it for him about 3 years ago and told him to treat with weedkilled and resand then reseal but he admitted that he didnt bother with the weedkiller so thats caused moss etc to appear under the sealer , its a job that im not fussed about as it seems like its way more trouble than its worth so il hit him with a huge price and he will go elsewere , thanks for all the replies