We have cleaned a lot of roofs and miles of siding. Next week I have a house to clean will green mildewed brick. I dont want to end up with a clean brick with a bunch of calcium leaching out. I plan on using the 7% siding wash that I use on vinyl. Any suggestions would be appreciated.
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All Washed Up 505 Carriage Hill Drive Forest, VA 24551 434-841-9889 David@AllWashed.com
Is the calcium already leaching out of the brick? If not, nothing in the wash should cause it to start. I'm also guessing 7 % won't be strong enough. We usually wasong brick at 15-20
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Ray Burke
Spray Wash Exterior Cleaning
850.528.3226
visit our website Soft Washing and Pressure Washing
Agree w Chuck. Apply it let it dwell. I use an adjustable wand so I can turn the pressure down and get right up on the brick and soft wash the stains. If it is really bad, let the customer know that there may be some residual stain left and that they need regular yearly maintenance to keep the brick and mortar clean. I have seen some house permanently damaged because they waited to long.
Sometimes to much pressure on brick will cause the "calcium" or "salts" to begin leaching out which is known as efflorescence. (Not every time) The proper mix as suggested above, along with a proper dwell time, will allow the work to be done without high pressure. Light pressure and decent GPM will do all you need.
On brick you can add a shot of sodium hydroxide to your mix to heat it up some.