Masonry Magazine August 2001 Page. 23
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Masonry has for centuries held the promise of durability, easy maintenance, and beauty more so than perhaps any other construction material. But in the face of skyrocketing construction costs and ever-tighter deadlines, masonry designs have changed. Contemporary masonry architecture, though economical, often short-circuits the very qualities of durability and low-maintenance the masonry was chosen for.
These designs leave brick, concrete and stone buildings vulnerable to water-the single most damaging element to masonry. Given time sometimes within a year water can stain and degrade a beautiful new masonry building. Lime run, efflorescence, biological staining - they're just a few of the water-based problems that get masonry contractors called back to the site after the job is done.
Contractors who understand and apply the art of masonry water repellents avoid these problems. Their work stands up to water and looks good for a long, long time.
HOW WATER EATS BUILDINGS
Rain, or water from other sources, soaks into masonry. The more porous the masonry, the more it absorbs. Inside the substrate, water dissolves the brick, stone or concrete's natural salts. Rain can also deposit dissolved salts as it soaks into the masonry. As the water evaporates out of the masonry, the salts recrystallize. When they recrystallize on the surface, you get efflorescence.
Ugly and very-hard-to-remove lime run occurs when the absorbed water dissolves calcium carbonate in the masonry. As the water migrates out through joints, cracks or weepholes, it (more on page 26)
Breathable, penetrating water repellents let the water vapor out of masonry while stopping liquid moisture from getting in. Photo by Gary Henry; Courtesy of PROSOCO
MASONRY AUGUST, 2001 23