Seal with silicone caulk because weatherization efforts should last or your savings won’t. Despite a common misperception, not all caulk provides energy savings over time. 100 percent silicone does.

Leaks frequently occur in and around homes in places where extreme temperature fluctuations, moisture, humidity, and damaging UV rays take their toll. Unlike acrylic caulk, which is vulnerable to these elements and can break down over time, silicone remains permanently flexible, shrink-proof, crack-proof, and waterproof. In fact, 100 percent silicone remains unaffected by all weather and temperature conditions, so it helps prevent gaps and cracks, through which energy dollars can pass, from reforming.

• Waterproof: Silicone is impervious to water, meaning water can't penetrate it and will never break it down. Once cured, it does not change or degrade—no shrinking, hardening, cracking, or crumbling. Even extreme temperatures, which often cause acrylic caulks to lose flexibility and degrade over time—leaving gaps for water to pass—do not affect silicone. 



• Flexible: Silicone stretches and compresses with joint movement as a house moves and settles. It remains permanently flexible and does not harden over time, which causes acrylic caulk to break—again, leaving cracks and gaps for air and water to pass.



• Shrink-proof: Silicone continues to fill the gap or crack as when first applied, helping prevent cracks from reforming.
   
• Crack-proof: Silicone remains unaffected by extreme heat and the sun, which cause acrylic caulk to crack over time.