In my other life, I sell technical products/solutions into road construction jobs. This usually involves writing papers/technical reports based on test results/case studies etc.. I use these to convince clients and designers to accept our systems. Most guys here in Sydney use high pressure to clean roofs, in fact, any literature I have found from tile manufacturers, roof repairers, Master Roffers Association etc. ALL recommend HP cleaning of roof tiles.. (tile manufacturers recommend RE ROOFING...LOL). Any of you guys want to help put a document together to technically market the advantages of LP roof cleaning?..Let me know