Comparing Water Repelling Penetrants on Antique Masonry

Abstract

Antique, or low fire, brick has suffered critical damage from repairs using Portland Cement, specifically water damage, as moisture cannot move equally throughout both materials. The effects of this water intrusion include spalling, stains, efflorescence, algae growth, and a decrease in insulating properties. The best way to continue preservation is to block moisture from entering the brick using a water repelling penetrant. This research will compare the most commonly used penetrants on low-fire brick and determine which product is best for preservation. Water repelling abilities as well as water vapor permeability will be tested using: Rilem tubes, a freeze/thaw chamber, and the ASTM water vapor permeability test. The penetrants being tested are: siloxane and room temperature vulcanizing (RTV) silicone.