Usually this dust is caused by the use of muriatic acid to clean the brick after it was initially installed.
Cleaning brick floors with muriatic acid.
Muriatic acid should never be used indoors and has to be thoroughly neutralized before disposal.
Muriatic acid is a solution of hydrogen chloride hcl in water also known as hydrochloric acid or fuming hydrochloric acid.
For cleaning of lighter colored bricks use a mixture of 1 part acid to 10 parts water.
When the moisture dries it leaves behind mineral deposits on the outside surfaces.
The general applications and uses of muriatic acid are mostly found in the pharmaceutical food petroleum and metal industry.
Muriatic acid is suitable for cleaning concrete masonry ceramics tiles bricks etc.
It will attack most of the materials it touches.
For darker bricks use 1 part acid to 20 parts water.
This dust is probably due to the grout between the bricks and the muriatic acid used in cleaning up after the grouting was finished.
However the white deposits are still apparent until they are cleaned off.
Never use metal paper or ceramic containers to mix the acid as they can cause an adverse chemical reation.
Muriatic acid is the strongest acid available to the public.
Use a large plastic or glass container only.
When the brick dries continue with one of the two following exterior solutions.
Masonry projects that use cement products like mortar concrete and grout can be messy muriatic acid is a sure way to clean masonry surfaces this product is a very strong acid that will clean dried cement products off stones bricks and other masonry surfaces.
When new sometimes brick flooring will have pale fine dust that seems to emit from its surface.
Let the brick absorb the cleaner for 3 5 minutes then use the water brush to scrub any residue off the brick.
Bleach or muriatic acid.
If the desired results are not achieved strengthen the concentration of the cleaner in the bucket and also scrub a little harder than during the first pass.
The fastest way to clean efflorescence from bricks and mortar is using a muriatic acid cleaning mixture.
This can cause a mess when tracked by feet to other floors.
Or you may find dust tracked from the brick flooring into other rooms.
Spray the dry brick down thoroughly with water from the garden hose.
Repeat this process until the brick is clean.
Once the humidity level in the masonry is gone efflorescence stops.
You need to keep flushing the brick flooring with water until the remaining muriatic acid stops leaking lime from the grout.
