January 13 - January 17, 2014
What’s the best way to protect a masonry wall from freeze/thaw cycling?
Alice Sloan of Klein and Hoffman, Inc. on
January 17, 2014:
Ensure mortar and sealant joints are sound and if a cavity wall, direct water to the exterior through proper flashing/drip edge/weeps.
Timothy Knell of Shore Corporation on
January 16, 2014:
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While every situation is unique, there are a few dos and don'ts. The key is to reduce the amount of moisture in the wall componenets. The penetration of water due to physical defects like poor mortar joints, cracked bricks, bad flashing, and gutters must be corrected first. An often overlooked source of water is "rising damp" or water wicking up into the wall from below grade sources. If one side of the wall is exposed to the elements and the other is heated or air conditioned, a breathable, water vapor-permeable water repellent may be appropriate. Most of these are based on silane, siloxane, or silicone technology and may range from invisible and penetrating to decorative surface coatings. They let water vapor move in and out of the wall based on weather conditions but prevent most wind-driven rain. Do not use a film-forming "water proofing" sealer as it will likely cause liquid water to be trapped in the wall and make the freeze / thaw damage worse.
Concrete masonry units (CMU);
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