The Air & Water Barrier is part of the manufacturer’s Masonry Veneer Installation System. Designed to protect against water intrusion, it is installed behind exterior wall claddings to produce air and water holdout. The low-VOC product can be used on a wide range of substrates such as wood, concrete, and brick. Cost: about $1.40 per square foot. Laticrete International. 800-243-4788. www.laticrete.com.