Ten years ago, caulks and sealants were part of a home's exterior weather barrier. Today, high-performance sealants are also used inside the house to keep conditioned air from escaping. This column looks at the best three sealants for residential air sealing: siliconized acrylic latex, silicone, and one-part polyurethane. Quality Counts Applying sealant is one of those jobs where skimping on quality will come back to haunt you later. The reason is the high level of stress found in most construction joints and the ease with which they can fail. A good sealant will stretch or compress as much as 25% of the original joint size. That exposes a 1/2- inch-wide joint to potential failure after a movement of only 1/8
