samanddallas

Muriatic acid should work or and is always great for any stone or masonry surface. If this doesn't work you could try Prosoco 600 Detergent or Prosoco Heavy Duty Paint Stripper both should be safe on the cobblestone. I'd love to hear what you used and how it turns out.

Thanks for the welcome! I'm glad I found this forum! I've already learned a ton. Today I found this on Craigslist...if you don't mind checking it out and letting me know what you think... Honda Pressure Washer 4000PSI Thanks

I've been shopping for the best 13hp pressure washer I can get under $1000. I want a 13hp Honda motor and need 4000psi with 3-4gpm ...any and all recommendations accepted ... thx sam

New here...I don't want to state the obvious but... Pros - Pressure washing a deck (wood or composite) is very efficient and will remove more of the dirt, moss & grime than scrubbing by hand. Depending on how bad the deck is you may or may not need to apply any chemicals. Cons - It is possible that some parts of the deck may be rotten in which case too high of pressure could blow out parts of the deck. This can be avoided by a quick but thorough inspection to all parts of the deck including hand rail prior to washing. The only other con I can think of is that if you have no experience doing this it is possible to apply too much pressure directly into the surface at close range which will destroy the wood even if it is not rotten. Hope this helps some. -sam