fowlerscleaning 14 Report post Posted April 9, 2010 Can anyone tell me what is the best chemical to use for pressure washing Split Block on a commercial building?? I've tried straight bleach and Purple Power. Share this post Link to post Share on other sites
Guy B 70 Report post Posted April 10, 2010 Depends on what you're trying to wash off. I've cleaned a lot of split block, whats on it? Pictures? Share this post Link to post Share on other sites
Chris Tharpe 40 Report post Posted April 10, 2010 Welcome Tim, post up a few pictures of the problem and someone will have seen it before. Share this post Link to post Share on other sites
fowlerscleaning 14 Report post Posted April 11, 2010 Its black fungus or something dunno but real bad. Share this post Link to post Share on other sites
Chris Tharpe 40 Report post Posted April 11, 2010 sounds like Mildew and 12% sodium hypochlorite applied 50/50 should take care of it and if not it will loosed it up quite a bit for you to put a wand on it and come off easily. If this block is near grass then you will have to water constantly in the areas your applying the 50/50 mix to hopefully keep from killing any grass or plants. Share this post Link to post Share on other sites
Christopher 102 Report post Posted April 12, 2010 Post some pictures so people here can help you. If the block has not been cleaned in over 10-15 years the stains might have become permanent into the pores. I ran across a building that was neglected for over 15 years and using the best chemicals from EacoChem, Prosoco, etc.....we could not get the stains out. We tried products with the HF acid in them, the regular cleaning chemicals, etc... over 20 different chemicals and the best we could do is a medium gray color residue. Split block or split faced block is very porous and needs regular cleaning. This property with the permanent stains looks like it is checker-boarded from far away from the pattern of smooth face/split face blocks. It really is a shame that it was neglected for so many years, now there are not too many options besides sand blasting or painting the blocks if they want it to look good. Share this post Link to post Share on other sites
