With foam, what must be done regarding joints to prevent leaks?

• A. Joints must be sealed to ensure no leaks or tongue and groove
• B. Joints must be sealed to ensure no leaks
• C. Joints must be left open
• D. No additional requirements

Answer: (A)

Foam works best when it creates a continuous air and moisture barrier, but that only happens if the seams and joints are sealed. Sealing joints fills any gaps where air, moisture, or water vapor could bypass the foam, preventing leaks and preserving insulation performance. Even joints that use tongue-and-groove profiles should be sealed along the seam to avoid hidden gaps. Leaving joints open undermines the barrier and risks leaks, while sealing joints keeps the system watertight and airtight. Use the appropriate sealant or foam sealant designed for the material and application to ensure a proper seal.