As always, the wall should be thoroughly saturated with water before and after any cleaning application. Also, a small inconspicuous area of wall should be tested to confirm that any solutions used will not harm the brick.
Freshly applied paint can be removed with a solution of trisodium phosphate mixed with water at a rate of 2 lb. per gallon of wat er. Apply the solution to the brick; allow it to soften paint; and remove with scraper and stiff bristle brush. Proprietary chemical compounds are also available through local distributors to remove fresh paint.
Existing paint which has been in place for some time is more difficult to remove and may require using abrasive techniques with non-steel scrapers or sandblasting by a professional. Certain brick should not be sandblasted. Proprietary chemical compounds from local distributors in the form of a gel solvent may be necessary to soften existing paint. Numerous applications may be necessary depending on the number of paint layers.
For additional information on removing paint from brickwork, see Technical Notes 20.