Brick's durability and longevity make it a well-known masonry material for construction and landscaping purposes. Homes, patios, retaining walls are commonly composed of brick. Brick surfaces, however, are not impervious to aesthetic blemishes from efflorescence, mortar spills and other stains. Hydrochloric acid, also known as muriatic acid, is a powerful chemical cleaning solution designed for dissolving stubborn stains on brick surface. Since hydrochloric acid is highly toxic and corrosive, it's generally used as a last resort solution when milder acids are unsuccessful.
Saturate the bricks and surrounding landscape with water to protect them from the hydrochloric acid. Cover the nearby shrubs, plants and grass with plastic dust sheets for added defence.
Put on with vinyl-coated coveralls, long sleeve clothing, acid-resistant rubber gloves, rubber boots and eye goggles for protection from the acid. Allow plenty of fresh air circulation to the area.
Fill a 3-gallon plastic bucket with 10 cups of water. Carefully pour 1 cup of hydrochloric acid into the bucket. Slowly stir the solution with a paint stir stick to thoroughly dissolve the acid in the water. Avoid splashing the acid solution.
Apply the acid solution to the bricks using a long handled nylon scrub brush. Let the acid solution permeate the bricks for 10 minutes.
Scour the bricks with the scrub brush to dissolve and loosen any efflorescence, mortar stains or stubborn grime.
Rinse the bricks with excessive amounts of water to wash away the acid solution.
Contact your local recycling centre for directions on how to properly and legally dispose of the acid solution.
Test the acid solution on a small hidden section of the bricks to ensure the hydrochloric acid doesn't discolour them.
Avoid direct contact with hydrochloric acid; it can severely burn skin and cause other serious health affects. Read the manufacturer's directions listed on the product's label for safety precautions. Adding water to hydrochloric acid can initiate an exothermic chemical reaction. Hydrochloric acid can damage and dissolve newly installed brick mortar.