GE Foam Gaps and Cracks VOC, GE-branded Gaps and Cracks Insulating Foam expands to seal gaps and cracks that are up to 1-inch in size. This durable foam sealant creates a weatherproof, water-resistant and airtight seal that blocks both pests and drafts. It also helps prevent damage from moisture and mold and mildew growth. With excellent adhesion to most building materials, it's suitable for indoor or outdoor applications, spot insulating, touch-ups and filling gaps and cracks in areas like basements, crawl spaces, foundations, under baseboards, around plumbing, around HVAC ductwork and more.