Removing effloresence

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CallMeVilla

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Got a large red brick patio near the beach. It has growing patches of white powdery effloresence (sp).

I have tried a relatively strong solution including phosphoric acid and scrubbing ... no help.

What is the best method for removing these white patches?
 
Thanks Neal, it was a classic in government bureaucratic over-writing which said: "Do not use acid, use a brush and water ..." No an effective solution and will require the number of slaves who built the pyramids.

Here are ideas I got ....

1. Vinegar
2. Phosphoric acid
3. Or ?

Still looking for the answer.
 
Try a pressure washer. I took a lot off a swimming pool with it once.
 
TSP (Tri Sodium Phosphate), scrub brush and a power washer.
 
We are in extreme water conservation in S. California, so the use of power washers is not recommended. In beach communities, water runoff is also prohibited. Double whammy.

Meeting with supplier tomorrow AM to find a solution (pun) to the problem. Probably acid-based using a neutralizer (sodium bicarbonate) in 5 minutes.

Will let y'all know .... and thanks for the feedback
 
I'm surprised to hear that your having this problem in the midst of a drought.
Moisture is needed to cause this.
 
Found the answer .... Here is the deal: We tried a product called Glaze n Seal efflorescence remover. Based on phosphoric acid and requires bicarbonate of soda to neutralize. Did not even dent the white powdery efflorescence.

Took it up a notch to Sure Klean 600 masonry cleaner. It is mostly used for new masonry to remove efflorescence and can be used on new concrete. It can be applied with a low pressure sprayer (50 psi max) and higher pressures are not recommended. It is a nitric acid cleaner which also needs neutralization and flushing after scrubbing.

We did a 4'x4' test panel is one corner. We pre-wet the area with water then applied a diluted solution of cleaner. They recommend between one part cleaner to 4-12 parts water. Our solution was stronger (1:3) because the client was anxious for results. It is recommended to wait 3-4 days to see if any discoloration develops in the bricks. We will do this based on the immediate results.

Plastic broom agitation of the cleaner, 5 minutes of wait time, neutralization for 5 minutes, then general flushing was used. After drying, the brinks were clean of both efflorescence and general dirt and scum. The client was elated ... we will wait until Monday to see if any discoloration develops.

I think this is a great solution to the problem.

SURE 600.jpg
 
vinegar is an acid which we use to rinse conc o'lays in the morning to negate effects of morning dew on conc,,, google prosoco
 
Did you try brushing it off dry? Some of those efflorescences are watersoluble...
 
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